702 research outputs found

    An International Comparison of Equity in Accessibility to Jobs: London, SĂŁo Paulo, and the Randstad

    Get PDF
    We analyze the impact of different accessibility measures on the interpretation of associated equity analysis using the Gini coefficient and the (pseudo) Palma ratio, and the impact of the method of assigning zonal accessibility on Gini estimation results using four different alternatives. Two types of potential accessibility measures (zonal and person-based) and two ratios of potential jobs to potential population (intra-modal and multi-modal) are estimated for car and transit in the Netherlands' Randstad region, Greater London, and SĂŁo Paulo relying on network data, schedule-based data, and speed profiles. Gini results are heavily influenced by the accessibility indicator and the method of assignment. The Palma ratio is also influenced by the choice of accessibility indicator, with the person-based potential accessibility measure tending to show greater inequity

    LA-ICP-MS/MS improves limits of detection in elemental bioimaging of gadolinium deposition originating from MRI contrast agents in skin and brain tissues

    Full text link
    © 2018 Elsevier GmbH A novel analytical method to detect the retention of gadolinium from contrast agents for magnetic resonance imaging (MRI) in tissue samples of patients is presented. It is based on laser ablation - inductively coupled plasma - triple quadrupole - mass spectrometry (LA-ICP-MS/MS). Both Gd and P were monitored with a mass shift of +16, corresponding to mono-oxygenated species, as well as Zn, Ca, and Fe on-mass. This method resulted in a significantly reduced background and improved limits of detection not only for phosphorus, but also for gadolinium. These improvements were essential to perform elemental bioimaging with improved resolution of 5 Όm x 5 Όm, allowing the detection of small Gd deposits in fibrotic skin and brain tumour tissue with diameters of approximately 50 Όm. Detailed analyses of these regions revealed that most Gd was accompanied with P and Ca, indicating co-precipitation

    Sweet spheres: Succession and CAZyme expression of marine bacterial communities colonizing a mix of alginate and pectin particles

    Get PDF
    Polysaccharide particles are important substrates and microhabitats for marine bacteria. However, substrate-specific bacterial dynamics in mixtures of particle types with different polysaccharide composition, as likely occurring in natural habitats, are undescribed. Here, we studied the composition, functional diversity and gene expression of marine bacterial communities colonising a mix of alginate and pectin particles. Amplicon, metagenome and metatranscriptome sequencing revealed that communities on alginate and pectin particles significantly differed from their free-living counterparts. Unexpectedly, microbial dynamics on alginate and pectin particles were similar, with predominance of amplicon sequence variants (ASVs) from Tenacibaculum, Colwellia, Psychrobium and Psychromonas. Corresponding metagenome-assembled genomes (MAGs) expressed diverse alginate lyases, several co-localised in polysaccharide utilisation loci. Only a single, low-abundant MAG showed elevated transcript abundances of pectin-degrading enzymes. One specific Glaciecola ASV dominated the free-living fraction, possibly persisting on particle-derived oligomers through different glycoside hydrolases. Elevated ammonium uptake and metabolism signified nitrogen as important factor for degrading carbon-rich particles, whereas elevated methylcitrate and glyoxylate cycles suggested nutrient limitation in surrounding waters. The bacterial preference for alginate, whereas pectin primarily served as colonization scaffold, illuminates substrate-driven dynamics within mixed polysaccharide pools. These insights expand our understanding of bacterial niche specialisation and the biological carbon pump in macroalgae-rich habitats

    Elastin-specific MRI of extracellular matrix-remodelling following hepatic radiofrequency-ablation in a VX2 liver tumor model

    Get PDF
    Hepatic radiofrequency ablation (RFA) induces a drastic alteration of the biomechanical environment in the peritumoral liver tissue. The resulting increase in matrix stiffness has been shown to significantly influence carcinogenesis and cancer progression after focal RF ablation. To investigate the potential of an elastin-specific MR agent (ESMA) for the assessment of extracellular matrix (ECM) remodeling in the periablational rim following RFA in a VX2 rabbit liver tumor-model, twelve New-Zealand-White-rabbits were implanted in the left liver lobe with VX2 tumor chunks from donor animals. RFA of tumors was performed using a perfused RF needle-applicator with a mean tip temperature of 70 degrees C. Animals were randomized into four groups for MR imaging and scanned at four different time points following RFA (week 0 [baseline], week 1, week 2 and week 3 after RFA), followed by sacrifice and histopathological analysis. ESMA-enhanced MR imaging was used to assess ECM remodeling. Gadobutrol was used as a third-space control agent. Molecular MR imaging using an elastin-specific probe demonstrated a progressive increase in contrast-to-noise ratio (CNR) (week 3: ESMA: 28.1 +/- 6.0; gadobutrol: 3.5 +/- 2.0), enabling non-invasive imaging of the peritumoral zone with high spatial-resolution, and accurate assessment of elastin deposition in the periablational rim. In vivo CNR correlated with ex vivo histomorphometry (ElasticaVanGiesson-stain, y=1.2x - 1.8, R-2=0.89, p<0.05) and gadolinium concentrations at inductively coupled mass spectroscopy (ICP-MS, y=0.04x+1.2, R-2=0.95, p<0.05). Laser-ICP-MS confirmed colocalization of elastin-specific probe with elastic fibers. Following thermal ablation, molecular imaging using an elastin-specific MR probe is feasible and provides a quantifiable biomarker for the assessment of the ablation-induced remodeling of the ECM in the periablational rim

    Gold nanoparticle distribution in advanced in vitro and ex vivo human placental barrier models

    Get PDF
    Gold nanoparticles (AuNPs) are promising candidates to design the next generation NP-based drug formulations specifically treating maternal, fetal or placental complications with reduced side effects. Profound knowledge on AuNP distribution and effects at the human placental barrier in dependence on the particle properties and surface modifications, however, is currently lacking. Moreover, the predictive value of human placental transfer models for NP translocation studies is not yet clearly understood, in particular with regards to differences between static and dynamic exposures. To understand if small (3–4 nm) AuNPs with different surface modifications (PEGylated versus carboxylated) are taken up and cross the human placental barrier, we performed translocation studies in a static human in vitro co-culture placenta model and the dynamic human ex vivo placental perfusion model. The samples were analysed using ICP-MS, laser ablation-ICP-MS and TEM analysis for sensitive, label-free detection of AuNPs

    Family coordination in families who have a child with autism spectrum disorder

    Get PDF
    Little is known about the interactions of families where there is a child with autism spectrum disorder (ASD). The present study applies the Lausanne Trilogue Play (LTP) to explore both its applicability to this population as well as to assess resources and areas of deficit in these families. The sample consisted of 68 families with a child with ASD, and 43 families with a typically developing (TD) child. With respect to the global score for family coordination there were several negative correlations: the more severe the symptoms (based on the child’s ADOS score), the more family coordination was dysfunctional. This correlation was particularly high when parents had to play together with the child. In the parts in which only one of the parents played actively with the child, while the other was simply present, some families did achieve scores in the functional range, despite the child’s symptom severity. The outcomes are discussed in terms of their clinical implications both for assessment and for interventio

    The effect of exercise on vastus medialis oblique muscle architecture: An ultrasound investigation.

    Get PDF
    The vastus medialis oblique (VMO) is thought to be implicated in patellofemoral pain (PFP), and weakness in this portion of the vastus medialis muscle may lead to PFP. Management includes physiotherapy to strengthen the VMO. Although this intervention has been shown to be effective, the effects on the architecture of the muscle have not been investigated. This study aims to determine the changes in VMO architecture following a program of strengthening exercises. Twenty-one male participants underwent an initial ultrasound scan to measure the fiber angle and the insertion level of the VMO on the patella. Each subject then undertook a 6-week quadriceps femoris strengthening program; the scan and measurements were then repeated. A significant increase in VMO fiber angle and insertion length was observed. Average fiber angle increased by 5.24°; average insertion length increased by 2.7 mm. There was found to be a significant negative correlation between the initial values and the degree of change. Pearson's coefficient of correlation for measurements of patella length taken before and after exercise was 0.921, indicating a high degree of reliability. There was a significant positive correlation between fiber angle change and declared level of compliance (R2 = 0.796). The results reported here indicate that physiotherapy leads to a significant change in VMO morphology. Given the inverse correlation noted between initial architectural parameters and the degree of change, we suggest that patients who would benefit most from physiotherapy can be identified in clinic using a simple ultrasound technique

    Anesthesia triggers drug delivery to experimental glioma in mice by hijacking caveolar transport

    Get PDF
    Abstract Background: Pharmaceutical intervention in the CNS is hampered by the shielding function of the blood-brain barrier (BBB). To induce clinical anesthesia, general anesthetics such as isoflurane readily penetrate the BBB. Here, we investigated whether isoflurane can be utilized for therapeutic drug delivery. Methods: Barrier function in primary endothelial cells was evaluated by transepithelial/transendothelial electrical resistance, and nanoscale STED and SRRF microscopy. In mice, BBB permeability was quantified by extravasation of several fluorescent tracers. Mouse models including the GL261 glioma model were evaluated by MRI, immunohistochemistry, electron microscopy, western blot, and expression analysis. Results: Isoflurane enhances BBB permeability in a time- and concentration-dependent manner. We demonstrate that, mechanistically, isoflurane disturbs the organization of membrane lipid nanodomains and triggers caveolar transport in brain endothelial cells. BBB tightness re-establishes directly after termination of anesthesia, providing a defined window for drug delivery. In a therapeutic glioblastoma trial in mice, simultaneous exposure to isoflurane and cytotoxic agent improves efficacy of chemotherapy. Conclusions: Combination therapy, involving isoflurane-mediated BBB permeation with drug administration has far-reaching therapeutic implications for CNS malignancies
    • 

    corecore