100 research outputs found
Measuring accessibility to jobs for the urban poor in Ahmedabad
Transport plays an integral role in the levels of mobility and socio-economic participation in any given society. Yet, traditional urban transport planning has neglected this important role and has limited its focus on the efficiency of the transport network itself, thereby overlooking the more difficult to measure socio-economic implications. This paper reports on the use of accessibility metrics for quantifying the effect of public transport and urban development interventions, such as BRT and social housing projects, in lowering the spatial mismatch between low income residents and their jobs, with examples from a World Bank commissioned project in Ahmedabad, India. In addition, we show how geo-spatial network modelling techniques can be used in measuring levels of accessibility for this purpose. Our findings show that the presented metrics and developed tool can highlight critical investment and policy reform needs for developing cities in India and beyond
Microdomains of the C-type lectin DC-SIGN are portals for virus entry into dendritic cells
The C-type lectin dendritic cell (DC)–specific intercellular adhesion molecule grabbing non-integrin (DC-SIGN; CD209) facilitates binding and internalization of several viruses, including HIV-1, on DCs, but the underlying mechanism for being such an efficient phagocytic pathogen-recognition receptor is poorly understood. By high resolution electron microscopy, we demonstrate a direct relation between DC-SIGN function as viral receptor and its microlocalization on the plasma membrane. During development of human monocyte-derived DCs, DC-SIGN becomes organized in well-defined microdomains, with an average diameter of 200 nm. Biochemical experiments and confocal microscopy indicate that DC-SIGN microdomains reside within lipid rafts. Finally, we show that the organization of DC-SIGN in microdomains on the plasma membrane is important for binding and internalization of virus particles, suggesting that these multimolecular assemblies of DC-SIGN act as a docking site for pathogens like HIV-1 to invade the host
Molecular characterization of MRSA collected during national surveillance between 2008 and 2019 in the Netherlands
Background.Although the Netherlands is a country with a low endemic level, methicillin-resistant Staphylococcus aureus (MRSA) poses a significant health care problem. Therefore, high coverage national MRSA surveillance has been in place since 1989. To monitor possible changes in the type-distribution and emergence of resistance and virulence, MRSA isolates are molecularly characterized.Methods.All 43,321 isolates from 36,520 persons, collected 2008–2019, were typed by multiple-locus variable number tandem repeats analysis (MLVA) with simultaneous PCR detection of the mecA, mecC and lukF-PV genes, indicative for PVL. Next-generation sequencing data of 4991 isolates from 4798 persons were used for whole genome multi-locus sequence typing (wgMLST) and identification of resistance and virulence genes.Results.We show temporal change in the molecular characteristics of the MRSA population with the proportion of PVL-positive isolates increasing from 15% in 2008–2010 to 25% in 2017–2019. In livestock-associated MRSA obtained from humans, PVL-positivity increases to 6% in 2017–2019 with isolates predominantly from regions with few pig farms. wgMLST reveals the presence of 35 genogroups with distinct resistance, virulence gene profiles and specimen origin. Typing shows prolonged persistent MRSA carriage with a mean carriage period of 407 days. There is a clear spatial and a weak temporal relationship between isolates that clustered in wgMLST, indicative for regional spread of MRSA strains.Conclusions.Using molecular characterization, this exceptionally large study shows genomic changes in the MRSA population at the national level. It reveals waxing and waning of types and genogroups and an increasing proportion of PVL-positive MRSA
Representations of time in human frontoparietal cortex
Precise time estimation is crucial in perception, action and social interaction. Previous neuroimaging studies in humans indicate that perceptual timing tasks involve multiple brain regions; however, whether the representation of time is localized or distributed in the brain remains elusive. Using ultra-high-field functional magnetic resonance imaging combined with multivariate pattern analyses, we show that duration information is decoded in multiple brain areas, including the bilateral parietal cortex, right inferior frontal gyrus and, albeit less clearly, the medial frontal cortex. Individual differences in the duration judgment accuracy were positively correlated with the decoding accuracy of duration in the right parietal cortex, suggesting that individuals with a better timing performance represent duration information in a more distinctive manner. Our study demonstrates that although time representation is widely distributed across frontoparietal regions, neural populations in the right parietal cortex play a crucial role in time estimation
Molecular characterization of MRSA collected during national surveillance between 2008 and 2019 in the Netherlands
Background.Although the Netherlands is a country with a low endemic level, methicillin-resistant Staphylococcus aureus (MRSA) poses a significant health care problem. Therefore, high coverage national MRSA surveillance has been in place since 1989. To monitor possible changes in the type-distribution and emergence of resistance and virulence, MRSA isolates are molecularly characterized.Methods.All 43,321 isolates from 36,520 persons, collected 2008-2019, were typed by multiple-locus variable number tandem repeats analysis (MLVA) with simultaneous PCR detection of the mecA, mecC and lukF-PV genes, indicative for PVL. Next-generation sequencing data of 4991 isolates from 4798 persons were used for whole genome multi-locus sequence typing (wgMLST) and identification of resistance and virulence genes.Results.We show temporal change in the molecular characteristics of the MRSA population with the proportion of PVL-positive isolates increasing from 15% in 2008-2010 to 25% in 2017-2019. In livestock-associated MRSA obtained from humans, PVL-positivity increases to 6% in 2017-2019 with isolates predominantly from regions with few pig farms. wgMLST reveals the presence of 35 genogroups with distinct resistance, virulence gene profiles and specimen origin. Typing shows prolonged persistent MRSA carriage with a mean carriage period of 407 days. There is a clear spatial and a weak temporal relationship between isolates that clustered in wgMLST, indicative for regional spread of MRSA strains.Conclusions.Using molecular characterization, this exceptionally large study shows genomic changes in the MRSA population at the national level. It reveals waxing and waning of types and genogroups and an increasing proportion of PVL-positive MRSA.A group of bacteria that cause difficult-to-treat infections in humans is methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study was to monitor changes in the spread of MRSA, their disease causing potential and resistance to antibiotics used to treat MRSA infections. MRSA from patients and their contacts in the Netherlands were collected over a period of 12 years and characterized. This revealed new types of MRSA emerged and others disappeared. An increasing number of MRSA produces a protein called PVL toxin, enabling MRSA to cause more severe infections. Also, some people appear to carry MRSA without any disease for more than a year. These findings suggest an increasing disease potential of MRSA and possible unnoticed sources of infection. Consequently, it is important to maintain monitoring of these infections to minimize MRSA spread.Schouls et al. characterize 43,321 methicillin-resistant Staphylococcus aureus (MRSA) isolates obtained between 2008 and 2019 in the Netherlands. Genomic changes occur in the MRSA population, with increases in the proportion of PVL-positive MRSA.Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc
Vision and visual history in elite-/near-elite level cricketers and rugby-league players
Background: The importance of optimal and/or superior vision for participation in high-level sport remains the subject of considerable clinical research interest. Here we examine the vision and visual history of elite/near-elite cricketers and rugby-league players.
Methods: Stereoacuity (TNO), colour vision, and distance (with/without pinhole) and near visual acuity (VA) were measured in two cricket squads (elite/international-level, female, n=16; near-elite, male, n=23) and one professional rugby-league squad (male, n=20). Refractive error was determined, and details of any correction worn and visual history were recorded.
Results: Overall, 63% had their last eye-examination within 2 years. However, some had not had an eye examination for 5 years, or had never had one (near-elite-cricketers: 30%; rugby-league players: 15%; elite-cricketers: 6%). Comparing our results for all participants to published data for young, optimally-corrected, non-sporting adults, distance VA was ~1 line of letters worse than expected. Adopting α=0.01, the deficit in distance-VA deficit was significant, but only for elite-cricketers (p0.02 for all comparisons). On average, stereoacuity was better than in young adults, but only in elite-cricketers (p<0.001; p=0.03, near-elite-cricketers; p=0.47, rugby-league -players). On-field visual issues were present in 27% of participants, and mostly (in 75% of cases) comprised uncorrected ametropia. Some cricketers (near-elite: 17.4%; elite: 38%) wore refractive correction during play but no rugby-league player did. Some individuals with prescribed correction choose not to wear it when playing.
Conclusion: Aside from near stereoacuity in elite-cricketers, these basic visual abilities were not better than equivalent, published data for optimally-corrected adults. 20-25% exhibited sub-optimal vision, suggesting that the clearest possible vision might not be critical for participation at the highest levels in the sports of cricket or rugby-league. Although vision could be improved in a sizeable proportion of our sample, the impact of correcting these, mostly subtle, refractive anomalies on playing performance is unknown
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
Synthesis of water-soluble scaffolds for peptide cyclization, labeling, and ligation
The synthesis and applications of water-soluble scaffolds that conformationally constrain side chain unprotected linear peptides containing two cysteines are described. These scaffolds contain a functionality with orthogonal reactivity to be used for labeling and ligation. This is illustrated by the chemical ligation of two dissimilar constrained peptides via oxime ligation or strain-promoted azide-alkyne cycloaddition in aqueous medi
- …