2,477 research outputs found
Data, Politics and Public Health: COVID-19 Data-Driven Decision Making in Public Discourse
In spring 2020, New York City became the acknowledged epicenter of the COVID-19 pandemic in the United States. To keep residents informed, Governor Cuomo conducted a streak of 111 daily press briefings reporting critical information about the status of the pandemic in the State at large, and New York City in particular. We show that through these briefings Governor Cuomo introduced an audience of New Yorkers and others to concepts basic to data-driven decision making such as data, science, models, and projections, and in so doing claimed that his decisions were unrelated to politics or whim. But we further suggest that data-driven decision making is not always immune from politics and human frailty in government. We conclude that basing policy decisions on data requires that policymakers insure the creation of a resilient and trustworthy health care data infrastructure to function as the scaffolding upon which policy making takes place
Municipal Government Use of Social Media: An Analysis of Three Chinese Cities
To investigate the use of information dissemination and public communication by Chinese municipal governments, we analyzed the social media use of three large cities with relatively mature social media development: Shanghai, Nanjing and Chengdu. We collected 4,429 government posts and users’ likes, shares and comments from Weibo accounts of each city’s information office. Government posts were coded into 7 types and 16 topics. We used cross-tabulation, correlation analysis and multivariate linear regression to analyze government posts, user responses and their inter-relationships. Chengdu has issued the most posts, while Nanjing has received the highest average user response to posts and exhibited the best signs of success in communication between the government and citizens
LPA, HGF, and EGF utilize distinct combinations of signaling pathways to promote migration and invasion of MDA-MB-231 breast carcinoma cells
BACKGROUND: Various pathways impinge on the actin-myosin pathway to facilitate cell migration and invasion including members of the Rho family of small GTPases and MAPK. However, the signaling components that are considered important for these processes vary substantially within the literature with certain pathways being favored. These distinctions in signaling pathways utilized are often attributed to differences in cell type or physiological conditions; however, these attributes have not been systematically assessed.
METHODS: To address this question, we analyzed the migration and invasion of MDA-MB-231 breast carcinoma cell line in response to various stimuli including lysophosphatidic acid (LPA), hepatocyte growth factor (HGF) and epidermal growth factor (EGF) and determined the involvement of select signaling pathways that impact myosin light chain phosphorylation.
RESULTS: LPA, a potent stimulator of the Rho-ROCK pathway, surprisingly did not require the Rho-ROCK pathway to stimulate migration but instead utilized Rac and MAPK. In contrast, LPA-stimulated invasion required Rho, Rac, and MAPK. Of these three major pathways, EGF-stimulated MDA-MB-231 migration and invasion required Rho; however, Rac was essential only for invasion and MAPK was dispensable for migration. HGF signaling, interestingly, utilized the same pathways for migration and invasion, requiring Rho but not Rac signaling. Notably, the dependency of HGF-stimulated migration and invasion as well as EGF-stimulated invasion on MAPK was subject to the inhibitors used. As expected, myosin light chain kinase (MLCK), a convergence point for MAPK and Rho family GTPase signaling, was required for all six conditions.
CONCLUSIONS: These observations suggest that, while multiple signaling pathways contribute to cancer cell motility, not all pathways operate under all conditions. Thus, our study highlights the plasticity of cancer cells to adapt to multiple migratory cues
Application of <sup>14</sup>C analyses to source apportionment of carbonaceous PM<sub>2.5</sub> in the UK
Determination of the radiocarbon (<sup>14</sup>C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM<sub>2.5</sub> were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of <sup>14</sup>C in both the total carbon, and in the organic and elemental carbon fractions, determined by two-stage combustion to CO<sub>2</sub>, graphitisation and quantification by accelerator mass spectrometry. OC and EC content was also determined by Sunset Analyzer. The mean fraction contemporary TC in the PM<sub>2.5</sub> samples was 0.50 (range 0.27–0.66, n = 26). There was no seasonality to the data, but there was a positive trend between fraction contemporary TC and magnitude of SOC/TC ratio and for the high values of these two parameters to be associated with air-mass back trajectories arriving in Birmingham from over land. Using a five-compartment mass balance model on fraction contemporary carbon in OC and EC, the following average source apportionment for the TC in these PM<sub>2.5</sub> samples was derived: 27% fossil EC; 20% fossil OC; 2% biomass EC; 10% biomass OC; and 41% biogenic OC. The latter category will comprise, in addition to BVOC-derived SOC, other non-combustion contemporary carbon sources such as biological particles, vegetative detritus, humic material and tyre wear. The proportion of total PM<sub>2.5</sub> at this location estimated to derive from BVOC-derived secondary organic aerosol was 9–29%. The findings from this work are consistent with those from elsewhere in Europe and support the conclusion of a significant and ubiquitous contribution from non-fossil biogenic sources to the carbon in terrestrial aerosol
Effect of maternal restricted diet during late gestation on muscle and bone development in sheep offspring
Changes in intrauterine environment, including nutrient availability, have been associated with fetal programming, contributing to different phenotypes which may determine health and susceptibility to disease throughout life. These changes seem to be mediated through alterations in both anabolic and catabolic hormone levels of maternal, placental and/or fetal origin. The present work aimed to evaluate how maternal under-nutrition during late pregnancy affects muscle and bone growth. Pregnant ewes were divided into two groups, one fed ad libitum and the other fed a restricted diet (50% of total energy requirements) during the last 6 weeks of gestation. Three twin carrying ewes from each feeding group were euthanized 6 days pre parturition. The remaining ewes gave birth normally and reared their lambs. At approximately day 30 post partum, 5 lambs from each of the feeding groups were euthanized and samples collected. Nutrient restriction during late gestation did not affect intrauterine axial growth, although weight at birth and the muscle weight were significantly lower than the ad libitum fed lamb fetuses. Bone development is less affected cf muscle development during periods of maternal feed restriction; however, catch-up growth of muscle occurs when lambs (30 days post-parturition) have access to adequate rations. In utero irrespective of maternal nutrient supply dry muscle mass is correlated (r=0.94) to bone development (bone weight, femur length and femur mineral density). In contrast, post partum growth of and skeleton are less tightly coupled and unaffected by the events in utero. A detailed examination of how maternal nutrient supply affects endocrine parameters in utero will be required to assess if it affects susceptibility post-partum to endocrine dysfunction.info:eu-repo/semantics/publishedVersio
Use of isotopically labeled substrates reveals kinetic differences between human and bacterial serine palmitoyltransferase
Isotope labels are frequently used tools to track metabolites through complex biochemical pathways and to discern the mechanisms of enzyme-catalysed reactions. Isotopically-labelled L-serine is often used to monitor the activity of the first enzyme in sphingolipid biosynthesis, serine palmitoyltransferase (SPT) as well as labelling downstream cellular metabolites. Intrigued by the effect that isotope labels may be having on SPT catalysis, we characterised the impact of different L-serine isotopologues on the catalytic activity of recombinant SPT isozymes from humans and the bacterium Sphingomonas paucimobilis. Our data show that S. paucimobilis SPT activity displays a clear isotope effect with [2,3,3-D] L-serine, whereas the human SPT isoform does not. This suggests that whilst both human and S. paucimobilis SPT catalyse the same chemical reaction, there may well be underlying subtle differences in their catalytic mechanisms. Our results suggest that it is that the activating small subunits of human SPT that play a key role in these mechanistic variations. This study also highlight that it is important to consider the type and location of isotope labels on a substrate when they are to be used in in vitro and in vivo studies
Putative degraders of low-density polyethylene-derived compounds are ubiquitous members of plastic associated bacterial communities in the marine environment
Research articleIt remains unknown whether and to what extent marine prokaryotic communities are capable of degrading plastic in the ocean. To address this knowledge gap, we combined enrichment experiments employing low-density polyethylene (LDPE) as the sole carbon source with a comparison of bacterial communities on plastic debris in the Pacific, the North Atlantic and the northern Adriatic Sea. A total of 35 operational taxonomic units (OTUs) were enriched in the LDPE-laboratory incubations after 1 year, of which 20 were present with relative abundances > 0.5% in at least one plastic sample collected from the environment. From these, OTUs classified as Cognatiyoonia, Psychrobacter, Roseovarius and Roseobacter were found in the communities of plastics collected at all oceanic sites. Additionally, OTUs classified as Roseobacter, Pseudophaeobacter, Phaeobacter, Marinovum and Cognatiyoonia, also enriched in the LDPE-laboratory incubations, were enriched on LDPE communities compared to the ones associated to glass and polypropylene in in-situ incubations in the northern Adriatic Sea after 1 month of incubation. Some of these enriched OTUs were also related to known alkane and hydrocarbon degraders. Collectively, these results demonstrate that there are prokaryotes capable of surviving with LDPE as the sole carbon source living on plastics in relatively high abundances in different water masses of the global ocean.Austrian Academy of Sciences, Austrian Sciences Fund, University of Viena, German Federal Ministry of Education and Science (BacGeoPac project (03G0248A) and IEO (RADPROF project)Versión del editor5,84
Characterization of the Taenia spp HDP2 sequence and development of a novel PCR-based assay for discrimination of Taenia saginata from Taenia asiatica
A previously described Taenia saginata HDP2 DNA sequence, a 4-kb polymorphic fragment, was previously used as the basis for developing PCR diagnostic protocols for the species-specific discrimination of T. saginata from T. solium and for the differentiation of T. saginata from T. asiatica. The latter was shown subsequently to lack the required specificity, so we undertook genetic studies of the HDP2 sequence from T. saginata and T. asiatica to determine why, and to develop a novel HDP2-PCR protocol for the simultaneous unambiguous identification of human taeniids. Sequencing and further analysis of the HDP2 DNA fragments of 19 Asiatic isolates of T. saginata and T. asiatica indicated that the HDP2 sequences of both species exhibited clear genomic variability, due to polymorphic variable fragments, that could correspond to the non-transcribed region of ribosomal DNA. This newly observed polymorphism allowed us to develop a novel, reproducible and reliable HDP2-PCR protocol which permitted the simultaneous discrimination of all T. saginata and T. asiatica isolates examined. This species-specific identification was based on, and facilitated by, the clear size difference in amplicon profiles generated: fragments of 1300 bp, 600 bp and 300 bp were produced for T. asiatica, amplicons of 1300 bp and 300 bp being obtained for T. saginata. Control T. solium samples produced one amplicon of 600 bp with the HDP2-PCR protocol. The assay has the potential to prove useful as a diagnostic tool in areas such as South East Asia where T. saginata, T. asiatica and T. solium coexist
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