355 research outputs found

    The association between threat and politics simultaneously depends on the type of threat, the political domain, and the country

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    Theories link threat with right-wing political beliefs. We use the World Values Survey (60,378 participants) to explore how six types of threat (e.g., economic, violence, and surveillance) are associated with multiple political beliefs (e.g., cultural, economic, and ideological identification) in 56 countries/territories. Multilevel models with individuals nested in countries revealed that the threat-political belief association depends on the type of threat, the type of political beliefs, and the country. Economic-related threats tended to be associated with more left-wing economic political beliefs and violence-related threats tended to be associated with more cultural right-wing beliefs, but there were exceptions to this pattern. Additional analyses revealed that the associations between threat and political beliefs were different across countries. However, our analyses identified few country characteristics that could account for these cross-country differences. Our findings revealed that political beliefs and perceptions of threat are linked, but that the relationship is not simple. Keywords: Ideology, Belief Systems, Threat, Cultur

    Arterial spin labeling signal in the CSF: implications for partial volume correction and blood-CSF barrier characterization

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    For better quantification of perfusion with arterial spin labeling (ASL), partial volume correction (PVC) is used to disentangle the signals from gray matter (GM) and white matter within any voxel. Based on physiological considerations, PVC algorithms typically assume zero signal in the cerebrospinal fluid (CSF). Recent measurements, however, have shown that CSF-ASL signal can exceed 10% of GM signal, even when using recommended ASL labeling parameters. CSF signal is expected to particularly affect PVC results in the choroid plexus. This study aims to measure the impact of CSF signal on PVC perfusion measurements, and to investigate the potential use of PVC to retrieve pure CSF-ASL signal for blood-CSF barrier characterization. In vivo imaging included six pCASL sequences with variable label duration and post-labeling delay (PLD), and an eight-echo 3D-GRASE readout. A dataset was simulated to estimate the effect of CSF-PVC with known ground-truth parameters. Differences between the results of CSF-PVC and non-CSF-PVC were estimated for regions of interest (ROls) based on GM probability, and a separate ROI isolating the choroid plexus. In vivo, the suitability of PVC-CSF signal as an estimate of pure CSF was investigated by comparing its time course with the long-TE CSF signal. Results from both simulation and in vivo data indicated that including the CSF signal in PVC improves quantification of GM CBF by approximately 10%. In simulated data, this improvement was greater for multi-PLD (model fitting) quantification than for single PLD (similar to 1-5% difference). In the choroid plexus, the difference between CSF-PVC and non-CSF-PVC was much larger, averaging around 30%. Long-TE (pure) CSF signal could not be estimated from PVC CSF signal as it followed a different time course, indicating the presence of residual macrovascular signal in the PVC. The inclusion of CSF adds value to PVC for more accurate measurements of GM perfusion, and especially for quantification of perfusion in the choroid plexus and study of the glymphatic system.Radiolog

    Periarticular Bone Changes in Osteoarthritis

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    Osteoarthritis (OA) can be considered an organ failure with pathological aspects in cartilage, bone, ligaments, and synovium. Altogether, these tissue changes can result in pain and immobilization—a failure of the joint. It is well regarded that OA is a complex multifactorial disease with many risk factors and different etiological pathways that all lead to an apparently similar end stage. Bony changes are clearly observed in advanced OA. However, little understanding exists on the role of these changes, whether they are a consequence of cartilage damage or precede this damage and maybe play an important role in the etiological process. Even more important is the issue of pain. Radiological scores of OA do not match well with pain and mobility scores, which questions the value of these scoring systems. It seems that we do not assess the most relevant parameters. Evaluation of conventional and new radiographic parameters is still an extensive part of the OA research field. We may have overlooked certain (subtle) parameters that can be extracted from x-rays, but other imaging modalities such as MRI, CT, or SPECT might better represent OA in a clinically relevant manner

    The beneficial effect of sulforaphane on platelet responsiveness during caloric load:a single-intake, double-blind, placebo-controlled, crossover trial in healthy participants

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    Background and aims: As our understanding of platelet activation in response to infections and/or inflammatory conditions is growing, it is becoming clearer that safe, yet efficacious, platelet-targeted phytochemicals could improve public health beyond the field of cardiovascular diseases. The phytonutrient sulforaphane shows promise for clinical use due to its effect on inflammatory pathways, favorable pharmacokinetic profile, and high bioavailability. The potential of sulforaphane to improve platelet functionality in impaired metabolic processes has however hardly been studied in humans. This study investigated the effects of broccoli sprout consumption, as a source of sulforaphane, on urinary 11-dehydro-thromboxane B2 (TXB2), a stable thromboxane metabolite used to monitor eicosanoid biosynthesis and response to antithrombotic therapy, in healthy participants exposed to caloric overload. Methods: In this double-blind, placebo-controlled, crossover trial 12 healthy participants were administered 16g of broccoli sprouts, or pea sprouts (placebo) followed by the standardized high-caloric drink PhenFlex given to challenge healthy homeostasis. Urine samples were collected during the study visits and analyzed for 11-dehydro-TXB2, sulforaphane and its metabolites. Genotyping was performed using Illumina GSA v3.0 DTCBooster. Results: Administration of broccoli sprouts before the caloric load reduced urinary 11-dehydro-TXB2 levels by 50% (p = 0.018). The amount of sulforaphane excreted in the urine during the study visits correlated negatively with 11-dehydro-TXB2 (rs = −0.377, p = 0.025). Participants carrying the polymorphic variant NAD(P)H dehydrogenase quinone 1 (NQO1*2) showed decreased excretion of sulforaphane (p = 0.035). Conclusion: Sulforaphane was shown to be effective in targeting platelet responsiveness after a single intake. Our results indicate an inverse causal relationship between sulforaphane and 11-dehydro-TXB2, which is unaffected by the concomitant intake of the metabolic challenge. 11-Dehydro-TXB2 shows promise as a non-invasive, sensitive, and suitable biomarker to investigate the effects of phytonutrients on platelet aggregation within hours. Clinical trial registration: [https://clinicaltrials.gov/], identifier [NCT05146804].</p

    Association of visit-to-visit variability in blood pressure with cognitive function in old age: prospective cohort study

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    &lt;p&gt;Objective To investigate the association between visit-to-visit variability in blood pressure and cognitive function in old age (&#62;70 years).&lt;/p&gt; &lt;p&gt;Design Prospective cohort study.&lt;/p&gt; &lt;p&gt;etting PROSPER (PROspective Study of Pravastatin in the Elderly at Risk) study, a collaboration between centres in Ireland, Scotland, and the Netherlands.&lt;/p&gt; &lt;p&gt;Participants 5461 participants, mean age 75.3 years, who were at risk of cardiovascular disease. Blood pressure was measured every three months during an average of 3.2 years. Visit-to-visit variability in blood pressure was defined as the standard deviation of blood pressure measurements between visits.&lt;/p&gt; &lt;p&gt;Main outcome measures Four domains of cognitive function, testing selective attention, processing speed, and immediate and delayed memory. In a magnetic resonance imaging substudy of 553 participants, structural brain volumes, cerebral microbleeds, infarcts, and white matter hyperintensities were measured.&lt;/p&gt; &lt;p&gt;Results Participants with higher visit-to-visit variability in systolic blood pressure had worse performance on all cognitive tests: attention (mean difference high versus low thirds) 3.08 seconds (95% confidence interval 0.85 to 5.31), processing speed −1.16 digits coded (95% confidence interval −1.69 to −0.63), immediate memory −0.27 pictures remembered (95% confidence interval −0.41 to −0.13), and delayed memory −0.30 pictures remembered (95% confidence interval −0.49 to −0.11). Furthermore, higher variability in both systolic and diastolic blood pressure was associated with lower hippocampal volume and cortical infarcts, and higher variability in diastolic blood pressure was associated with cerebral microbleeds (all P&#60;0.05). All associations were adjusted for average blood pressure and cardiovascular risk factors.&lt;/p&gt; Conclusion Higher visit-to-visit variability in blood pressure independent of average blood pressure was associated with impaired cognitive function in old age

    Parkinson's disease-related perfusion and glucose metabolic brain patterns identified with PCASL-MRI and FDG-PET imaging

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    AbstractIntroductionUnder normal conditions, the spatial distribution of resting cerebral blood flow and cerebral metabolic rate of glucose are closely related. A relatively new magnetic resonance (MR) technique, pseudo-continuous arterial spin labeling (PCASL), can be used to measure regional brain perfusion. We identified a Parkinson's disease (PD)-related perfusion and metabolic covariance pattern in the same patients using PCASL and FDG-PET imaging and assessed (dis)similarities in the disease-related pattern between perfusion and metabolism in PD patients.MethodsNineteen PD patients and seventeen healthy controls underwent [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. Of 14 PD patients and all healthy controls PCASL-MRI could be obtained. Data were analyzed using scaled subprofile model/principal component analysis (SSM/PCA).ResultsUnique Parkinson's disease-related perfusion and metabolic covariance patterns were identified using PCASL and FDG-PET in the same patients. The PD-related metabolic covariance brain pattern is in high accordance with previously reports. Also our disease-related perfusion pattern is comparable to the earlier described perfusion pattern. The most marked difference between our perfusion and metabolic patterns is the larger perfusion decrease in cortical regions including the insula.ConclusionWe identified PD-related perfusion and metabolic brain patterns using PCASL and FDG-PET in the same patients which were comparable with results of existing research. In this respect, PCASL appears to be a promising addition in the early diagnosis of individual parkinsonian patients

    Qualitative and Mixed Methods Social Media Research: A Review of the Literature

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    Social media technologies have attracted substantial attention among many types of users including researchers who have published studies for several years. This article presents an overview of trends in qualitative and mixed methods social media research literature published from 2007 through 2013. A collection of 229 qualitative studies were identified through a systematic literature review process. A subset of 55 of these articles report studies involving a combination of qualitative and quantitative methods. Articles were reviewed, analyzed, and coded through a qualitative content analysis approach. Overall trends are presented with respect to the entire collection of articles followed by an analysis of mixed methods research approaches identified in the subset of 55 studies. The most commonly used research approaches involved collecting data from people through interview, focus group, and survey methodologies. Content analysis was the second most commonly used approach whereby researchers use Facebook posts, Tweets (Twitter posts), YouTube videos, or other social media content as a data source. Many of the studies involving combinations of quantitative and qualitative data followed a design resembling Creswell and Plano Clark’s basic mixed methods typology (e.g., convergent parallel, explanatory sequential, and exploratory sequential)

    The use of variable delay multipulse chemical exchange saturation transfer for separately assessing different CEST pools in the human brain at 7T

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    Purpose Current challenges of in vivo CEST imaging include overlapping signals from different pools. The overlap arises from closely resonating pools and/or the broad magnetization transfer contrast (MTC) from macromolecules. This study aimed to evaluate the feasibility of variable delay multipulse (VDMP) CEST to separately assess solute pools with different chemical exchange rates in the human brain in vivo, while mitigating the MTC. Methods VDMP saturation buildup curves were simulated for amines, amides, and relayed nuclear Overhauser effect. VDMP data were acquired from glutamate and bovine serum albumin phantoms, and from six healthy volunteers at 7T. For the in vivo data, MTC removal was performed via a three-pool Lorentzian fitting. Different B-1 amplitudes and mixing times were used to evaluate CEST pools with different exchange rates. Results The results show the importance of removing MTC when applying VDMP in vivo and the influence of B-1 for distinguishing different pools. Finally, the optimal B-1 and mixing times to effectively saturate slow- and fast-exchanging components are also reported. Slow-exchanging amides and rNOE components could be distinguished when using B-1 = 1 mu T and t(mix) = 10 ms and 40 ms, respectively. Fast-exchanging components reached the highest saturation when using a B-1 = 2.8 mu T and t(mix) = 0 ms. Conclusion VDMP is a powerful CEST-editing tool, exploiting chemical exchange-rate differences. After MTC removal, it allows separate assessment of slow- and fast-exchanging solute pools in in vivo human brain.Neuro Imaging Researc
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