443 research outputs found
Knowledge-Bearing Elites and Industrial Performance in France and Germany. CES Germany & Europe Working Papers, No. 04.5, December 1993
Most comparative studies of public policies for competitiveness focus on the links among public agencies and industrial sectors. This paper argues that the professions---or knowledge-bearing elites-that animate these organizational links are equally significant. For public policies to promote technological advance, the visions and self-images of knowledge-bearing elites are par ticularly important. By examining administrative and technical elites in France and Germany in the 1980s, the paper identifies characteristics that enable these elites to implement policy in some cases, but not in others. France's "state-created" elites were well-positioned to initiate and implement large technology projects, such as digitizing the telecommunications network. Germany's state-recognized elites were, by contrast, better positioned to facilitate framework oriented programs that aimed at the diffusion of new technologies throughout industry. The linkages among administrative and technical elites also explain why French policymakers had difficulty adapting policy to changing circumstances over time while German policymakers managed in many cases to learn more from previous policy experiences and to adapt subsequent initiatives accordingly
Adipocytes enhance murine pancreatic cancer growth via a hepatocyte growth factor (HGF)-mediated mechanism
INTRODUCTION:
Obesity accelerates the development and progression of pancreatic cancer, though the mechanisms underlying this association are unclear. Adipocytes are biologically active, producing factors such as hepatocyte growth factor (HGF) that may influence tumor progression. We therefore sought to test the hypothesis that adipocyte-secreted factors including HGF accelerate pancreatic cancer cell proliferation.
MATERIAL AND METHODS:
Murine pancreatic cancer cells (Pan02 and TGP-47) were grown in a) conditioned medium (CM) from murine F442A preadipocytes, b) HGF-knockdown preadipocyte CM, c) recombinant murine HGF at increasing doses, and d) CM plus HGF-receptor (c-met) inhibitor. Cell proliferation was measured using the MTT assay. ANOVA and t-test were applied; p < 0.05 considered significant.
RESULTS:
Wild-type preadipocyte CM accelerated Pan02 and TGP-47 cell proliferation relative to control (59 ± 12% and 34 ± 12%, p < 0.01, respectively). Knockdown of preadipocyte HGF resulted in attenuated proliferation vs. wild type CM in Pan02 cells (35 ± 5% vs. 68 ± 14% greater than control; p < 0.05), but proliferation in TGP-47 cells remained unchanged. Recombinant HGF dose-dependently increased Pan02, but not TGP-47, proliferation (p < 0.05). Inhibition of HGF receptor, c-met, resulted in attenuated proliferation versus control in Pan02 cells, but not TGP-47 cells.
CONCLUSIONS:
These experiments demonstrate that adipocyte-derived factors accelerate murine pancreatic cancer proliferation. In the case of Pan02 cells, HGF is responsible, in part, for this proliferation
Widespread seasonal gene expression reveals annual differences in human immunity and physiology.
Seasonal variations are rarely considered a contributing component to human tissue function or health, although many diseases and physiological process display annual periodicities. Here we find more than 4,000 protein-coding mRNAs in white blood cells and adipose tissue to have seasonal expression profiles, with inverted patterns observed between Europe and Oceania. We also find the cellular composition of blood to vary by season, and these changes, which differ between the United Kingdom and The Gambia, could explain the gene expression periodicity. With regards to tissue function, the immune system has a profound pro-inflammatory transcriptomic profile during European winter, with increased levels of soluble IL-6 receptor and C-reactive protein, risk biomarkers for cardiovascular, psychiatric and autoimmune diseases that have peak incidences in winter. Circannual rhythms thus require further exploration as contributors to various aspects of human physiology and disease.The Gambian study providing data for analysis was supported by core funding MC-A760-5QX00 to the International Nutrition Group by the UK Medical Research Council (MRC) and the UK Department for the International Development (DFID) under the MRC/DFID Concordat agreement. This work was supported by the JDRF UK Centre for Diabetes-Genes, Autoimmunity and Prevention (D-GAP; 4-2007-1003), the JDRF (9-2011-253), the Wellcome Trust (WT061858/091157), the National Institute for Health Research Cambridge Biomedical Research Centre (CBRC) and the Medical Research Council (MRC) Cusrow Wadia Fund. The research leading to these results has received funding from the European Union’s 7th Framework Programme (FP7/2007–2013) under grant agreement no.241447 (NAIMIT). The Cambridge Institute for Medical Research (CIMR) is in receipt of a Wellcome Trust Strategic Award (WT100140). X.C.D. was a University of Cambridge/Wellcome Trust Infection and Immunity PhD student. R.C.F. is funded by a JDRF post-doctoral fellowship (3-2011-374). C.W. and H.G are funded by the Wellcome Trust (WT089989). The BABYDIET study was supported by grants from the Deutsche Forschungsgemeinschaft (DFG ZI-310/14-1 to-4), the JDRF (JDRF 17-2012-16 and 1-2006-665) and the German Center for Diabetes Research (DZD e.V.). E.B. is supported by the DFG Research Center and Cluster of Excellence—Center for Regenerative Therapies Dresden (FZ 111).This is the final published version. It first appeared at http://www.nature.com/ncomms/2015/150512/ncomms8000/full/ncomms8000.html
KELT-8b: A highly inflated transiting hot Jupiter and a new technique for extracting high-precision radial velocities from noisy spectra
We announce the discovery of a highly inflated transiting hot Jupiter
discovered by the KELT-North survey. A global analysis including constraints
from isochrones indicates that the V = 10.8 host star (HD 343246) is a mildly
evolved, G dwarf with K, , , an inferred mass
M, and radius
R. The planetary companion has mass , radius
, surface gravity , and density
g cm. The planet is on a roughly
circular orbit with semimajor axis AU and
eccentricity . The best-fit linear ephemeris is
BJD and
days. This planet is one of the most inflated of all known transiting
exoplanets, making it one of the few members of a class of extremely low
density, highly-irradiated gas giants. The low stellar and large
implied radius are supported by stellar density constraints from follow-up
light curves, plus an evolutionary and space motion analysis. We also develop a
new technique to extract high precision radial velocities from noisy spectra
that reduces the observing time needed to confirm transiting planet candidates.
This planet boasts deep transits of a bright star, a large inferred atmospheric
scale height, and a high equilibrium temperature of
K, assuming zero albedo and perfect heat redistribution, making it one of the
best targets for future atmospheric characterization studies.Comment: Submitted to ApJ, feedback is welcom
ULTRA-SHORT-PERIOD PLANETS IN K2 WITH COMPANIONS: A DOUBLE TRANSITING SYSTEM FOR EPIC 220674823
Two transiting planets have been identified orbiting K2 target EPIC 220674823. One object is an ultra-short-period planet (USP) with a period of just 0.57 days (13.7 hr), while the other has a period of 13.3 days. Both planets are small, with the former having a radius of R_(p1) = 1.5 R⊕ and the latter R_(p2) = 2.5 R⊕. Follow-up observations, including radial velocity (with uncertainties of 110 m s−1) and high-resolution adaptive optics imagery, show no signs of stellar companions. EPIC 220674823 is the 12th confirmed or validated planetary system in which a USP (i.e., having an orbital period less than 1 day) is accompanied by at least one additional planet, suggesting that such systems may be common and must be accounted for in models for the formation and evolution of such extreme systems
Sources of heterogeneity in human monocyte subsets
AbstractHuman monocytes are commonly defined and discriminated by the extent of their cell surface expression of CD14 and CD16, with associated differences in function and phenotype related to the intensity of expression of these markers. With increasing interest into the function and behaviour of monocytes, it is important to have a clear understanding of how differing strategies of analysis can affect results and how different protocols and population backgrounds can affect this highly morphogenic cell type.Using PBMCs from populations with differing ethnicities and histories of parasite exposure we have characterized monocyte phenotype based on intensity of CD14 and CD16 expression. Using the surface markers HLA-DR, CCR2 and CX3CR1, we compared monocyte phenotype between populations and further assessed changes in monocytes with freezing and thawing of PBMCs.Our results reveal that there is a progression of surface marker expression based on intensity of CD14 or CD16 expression, stressing the importance of careful gating of monocyte subtypes. Freezing and thawing of the PBMCs has no effect generally on the monocytes, although it does lead to a decrease in CD16 and CX3CR1 expression. We show that there are differences in the monocyte populations based on ethnicity and history of exposure to the common parasites Plasmodium falciparum and Schistosoma haematobium.This study highlights that blood monocytes consist of a continuous population of cells, within which the dominant phenotype may vary dependent on the background of the study population. Comparing results from monocyte studies therefore needs to be done with great care, as ethnic background of donor population, gating strategy and processing of PBMCs may all have an effect on outcome of monocyte phenotype
Non-linear electromagnetic response of graphene
It is shown that the massless energy spectrum of electrons and holes in
graphene leads to the strongly non-linear electromagnetic response of this
system. We predict that the graphene layer, irradiated by electromagnetic
waves, emits radiation at higher frequency harmonics and can work as a
frequency multiplier. The operating frequency of the graphene frequency
multiplier can lie in a broad range from microwaves to the infrared.Comment: 5 pages, 3 figure
Variation in the Microbiota of Ixodes Ticks with Regard to Geography, Species, and Sex
Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex
Clinical, radiologic, pathologic, and molecular characteristics of long-term survivors of diffuse intrinsic pontine glioma (DIPG): a collaborative report from the International and European Society for Pediatric Oncology DIPG registries
Purpose Diffuse intrinsic pontine glioma (DIPG) is a brainstem malignancy with a median survival of < 1 year. The International and European Society for Pediatric Oncology DIPG Registries collaborated to compare clinical, radiologic, and histomolecular characteristics between short-term survivors (STSs) and long-term survivors (LTSs). Materials and Methods Data abstracted from registry databases included patients from North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the United Kingdom, and Croatia. Results Among 1,130 pediatric and young adults with radiographically confirmed DIPG, 122 (11%) were excluded. Of the 1,008 remaining patients, 101 (10%) were LTSs (survival ≥ 2 years). Median survival time was 11 months (interquartile range, 7.5 to 16 months), and 1-, 2-, 3-, 4-, and 5-year survival rates were 42.3% (95% CI, 38.1% to 44.1%), 9.6% (95% CI, 7.8% to 11.3%), 4.3% (95% CI, 3.2% to 5.8%), 3.2% (95% CI, 2.4% to 4.6%), and 2.2% (95% CI, 1.4% to 3.4%), respectively. LTSs, compared with STSs, more commonly presented at age < 3 or > 10 years (11% v 3% and 33% v 23%, respectively; P < .001) and with longer symptom duration ( P < .001). STSs, compared with LTSs, more commonly presented with cranial nerve palsy (83% v 73%, respectively; P = .008), ring enhancement (38% v 23%, respectively; P = .007), necrosis (42% v 26%, respectively; P = .009), and extrapontine extension (92% v 86%, respectively; P = .04). LTSs more commonly received systemic therapy at diagnosis (88% v 75% for STSs; P = .005). Biopsies and autopsies were performed in 299 patients (30%) and 77 patients (10%), respectively; 181 tumors (48%) were molecularly characterized. LTSs were more likely to harbor a HIST1H3B mutation (odds ratio, 1.28; 95% CI, 1.1 to 1.5; P = .002). Conclusion We report clinical, radiologic, and molecular factors that correlate with survival in children and young adults with DIPG, which are important for risk stratification in future clinical trials
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