549 research outputs found
The Origins of the Service State: On the Ironies of Intervention
This essay discusses the growth of the interventionist service state in the United States since the 1890s. It indicates how the exhaustion of the national entrepreneurial capitalist model necessitated state management of the economy, society and culture in order to consolidate the emergence of a transnational monopoly capitalist mode of economic growth. These bureaucratic interventions, however, from the 1930s through the 1970s dangerously eroded the continuing reproduction of civil society. Hence, the new social movements of the 1960s and 1970s are discussed as popular efforts to countervail the bureaucratic logic of monopoly capital and the service state. The new social movements\u27 focus on popular participation, community-building and political empowerment, in turn, might provide the organizational basis for creating new democratic economic, political and social alternatives to the over-administered consumer society constructed by the service state and transnational capital during the 20th century
Pluto's Light Curve in 1933-1934
We are reporting on a new accurate photographic light curve of Pluto for
1933-1934 when the heliocentric distance was 40 AU. We used 43 B-band and
V-band images of Pluto on 32 plates taken on 15 nights from 19 March 1933 to 10
March 1934. Most of these plates were taken with the Mount Wilson 60" and 100"
telescopes, but 7 of the plates (now at the Harvard College Observatory) were
taken with the 12" and 16" Metcalf doublets at Oak Ridge. The plates were
measured with an iris diaphragm photometer, which has an average one-sigma
photometric error on these plates of 0.08 mag as measured by the repeatability
of constant comparison stars. The modern B and V magnitudes for the comparison
stars were measured with the Lowell Observatory Hall 1.1-m telescope. The
magnitudes in the plate's photographic system were converted to the Johnson B-
and V-system after correction with color terms, even though they are small in
size. We find that the average B-band mean opposition magnitude of Pluto in
1933-1934 was 15.73 +- 0.01, and we see a roughly sinusoidal modulation on the
rotational period (6.38 days) with a peak-to-peak amplitude of 0.11 +- 0.03
mag. With this, we show that Pluto darkened by 5% from 1933-1934 to 1953-1955.
This darkening from 1933-1934 to 1953-1955 cannot be due to changing viewing
geometry (as both epochs had identical sub-Earth latitudes), so our
observations must record a real albedo change over the southern hemisphere. The
later darkening trend from 1954 to the 1980s has been explained by changing
viewing geometry (as more of the darker northern hemisphere comes into view).
Thus, we now have strong evidence for albedo changes on the surface of Pluto,
and these are most easily explained by the systematic sublimation of frosts
from the sunward pole that led to a drop in the mean surface albedo.Comment: Icarus in press, 24 page
The nuclear condition in the twenty-first century:Techno-political aspects in historical and contemporary perspectives
A morphometric analysis of vegetation patterns in dryland ecosystems
Vegetation in dryland ecosystems often forms remarkable spatial patterns. These range from regular bands of vegetation alternating with bare ground, to vegetated spots and labyrinths, to regular gaps of bare ground within an otherwise continuous expanse of vegetation. It has been suggested that spotted vegetation patterns could indicate that collapse into a bare ground state is imminent, and the morphology of spatial vegetation patterns, therefore, represents a potentially valuable source of information on the proximity of regime shifts in dryland ecosystems. In this paper, we have developed quantitative methods to characterize the morphology of spatial patterns in dryland vegetation. Our approach is based on algorithmic techniques that have been used to classify pollen grains on the basis of textural patterning, and involves constructing feature vectors to quantify the shapes formed by vegetation patterns. We have analysed images of patterned vegetation produced by a computational model and a small set of satellite images from South Kordofan (South Sudan), which illustrates that our methods are applicable to both simulated and real-world data. Our approach provides a means of quantifying patterns that are frequently described using qualitative terminology, and could be used to classify vegetation patterns in large-scale satellite surveys of dryland ecosystems
Neutralizing Antibody-Resistant Hepatitis C Virus Cell-to-Cell Transmission
Hepatitis C virus (HCV) can initiate infection by cell-free particle and cell-cell contact-dependent transmission. In this study we use a novel infectious coculture system to examine these alternative modes of infection. Cell-to-cell transmission is relatively resistant to anti-HCV glycoprotein monoclonal anti- bodies and polyclonal immunoglobulin isolated from infected individuals, providing an effective strategy for escaping host humoral immune responses. Chimeric viruses expressing the structural proteins rep- resenting the seven major HCV genotypes demonstrate neutralizing antibody-resistant cell-to-cell trans- mission. HCV entry is a multistep process involving numerous receptors. In this study we demonstrate that, in contrast to earlier reports, CD81 and the tight-junction components claudin-1 and occludin are all essential for both cell-free and cell-to-cell viral transmission. However, scavenger receptor BI (SR-BI) has a more prominent role in cell-to-cell transmission of the virus, with SR-BI-specific antibodies and small-molecule inhibitors showing preferential inhibition of this infection route. These observations highlight the importance of targeting host cell receptors, in particular SR-BI, to control viral infection and spread in the liver
Deep learning cardiac motion analysis for human survival prediction
Motion analysis is used in computer vision to understand the behaviour of
moving objects in sequences of images. Optimising the interpretation of dynamic
biological systems requires accurate and precise motion tracking as well as
efficient representations of high-dimensional motion trajectories so that these
can be used for prediction tasks. Here we use image sequences of the heart,
acquired using cardiac magnetic resonance imaging, to create time-resolved
three-dimensional segmentations using a fully convolutional network trained on
anatomical shape priors. This dense motion model formed the input to a
supervised denoising autoencoder (4Dsurvival), which is a hybrid network
consisting of an autoencoder that learns a task-specific latent code
representation trained on observed outcome data, yielding a latent
representation optimised for survival prediction. To handle right-censored
survival outcomes, our network used a Cox partial likelihood loss function. In
a study of 302 patients the predictive accuracy (quantified by Harrell's
C-index) was significantly higher (p < .0001) for our model C=0.73 (95 CI:
0.68 - 0.78) than the human benchmark of C=0.59 (95 CI: 0.53 - 0.65). This
work demonstrates how a complex computer vision task using high-dimensional
medical image data can efficiently predict human survival
Conversion of sub-tropical native vegetation to introduced conifer forest: Impacts on below-ground and above-ground carbon pools
Land-use change can have a major influence on soil organic carbon (SOC) and above-ground C pools. We assessed a change from native vegetation to introduced Pinus species plantations on C pools using eight paired sites. At each site we determined the impacts on 0–50 cm below-ground (SOC, charcoal C, organic matter C, particulate organic C, humic organic C, resistant organic C) and above-ground (litter, coarse woody debris, standing trees and woody understorey plants) C pools. In an analysis across the different study sites there was no significant difference (P > 0.05) in SOC or above-ground tree C stocks between paired native vegetation and pine plantations, although significant differences did exist at specific sites. SOC (calculated based on an equivalent soil mass basis) was higher in the pine plantations at two sites, higher in the native vegetation at two sites and did not differ for the other four sites. The site to site variation in SOC across the landscape was far greater than the variation observed with a change from native vegetation to introduced Pinus plantation. Differences between sites were not explained by soil type, although tree basal area was positively correlated with 0–50 cm SOC. In fact, in the native vegetation there was a significant linear relationship between above-ground biomass and SOC that explained 88.8% of the variation in the data. Fine litter C (0–25 mm diameter) tended to be higher in the pine forest than in the adjacent native vegetation and was significantly higher in the pine forest at five of the eight paired sites. Total litter C (0–100 mm diameter) increased significantly with plantation age (R2 = 0.64). Carbon stored in understorey woody plants (2.5–10 cm DBH) was higher in the native vegetation than in the adjacent pine forest. Total site C varied greatly across the study area from 58.8 Mg ha−1 at a native heathland site to 497.8 Mg ha−1 at a native eucalypt forest site. Our findings suggest that the effects of change from native vegetation to introduced Pinus sp. forest are highly site-specific and may be positive, negative, or have no influence on various C pools, depending on local site characteristics (e.g. plantation age and type of native vegetation)
Continuous subcutaneous insulin infusion alters microRNA expression and glycaemic variability in children with type 1 diabetes
To determine whether continuous subcutaneous insulin infusion (CSII) vs. multiple daily injections (MDI) therapy from near-diagnosis of type 1 diabetes is associated with reduced glycaemic variability (GV) and altered microRNA (miRNAs) expression. Adolescents (74% male) within 3-months of diabetes diagnosis (n = 27) were randomized to CSII (n = 12) or MDI. HbA1c, 1-5-Anhydroglucitol (1,5-AG), high sensitivity C-peptide and a custom TaqMan qPCR panel of 52 miRNAs were measured at baseline and follow-up (median (LQ-UQ); 535 (519-563) days). There were no significant differences between groups in baseline or follow-up HbA1c or C-peptide, nor baseline miRNAs. Mean +/- SD 1,5-AG improved with CSII vs. MDI (3.1 +/- 4.1 vs. - 2.2 +/- - 7.0 mg/ml respectively, P = 0.029). On follow-up 11 miRNAs associated with diabetes vascular complications had altered expression in CSII-users. Early CSII vs. MDI use is associated with lower GV and less adverse vascular-related miRNAs. Relationships with future complications are of interest
Calorie restriction activates new adult born olfactory‐bulb neurones in a ghrelin‐dependent manner but acyl‐ghrelin does not enhance subventricular zone neurogenesis
The ageing and degenerating brain show deficits in neural stem/progenitor cell (NSPC) plasticity that are accompanied by impairments in olfactory discrimination. Emerging evidence suggests that the gut hormone ghrelin plays an important role in protecting neurones, promoting synaptic plasticity and increasing hippocampal neurogenesis in the adult brain. In the present study, we investigated the role of ghrelin with respect to modulating adult subventricular zone (SVZ) NSPCs that give rise to new olfactory bulb (OB) neurones. We characterised the expression of the ghrelin receptor, growth hormone secretagogue receptor (GHSR), using an immunohistochemical approach in GHSR‐eGFP reporter mice to show that GHSR is expressed in several regions, including the OB but not in the SVZ of the lateral ventricle. These data suggest that acyl‐ghrelin does not mediate a direct effect on NSPC in the SVZ. Consistent with these findings, treatment with acyl‐ghrelin or genetic silencing of GHSR did not alter NSPC proliferation within the SVZ. Similarly, using a bromodeoxyuridine pulse‐chase approach, we show that peripheral treatment of adult rats with acyl‐ghrelin did not increase the number of new adult‐born neurones in the granule cell layer of the OB. These data demonstrate that acyl‐ghrelin does not increase adult OB neurogenesis. Finally, we investigated whether elevating ghrelin indirectly, via calorie restriction (CR), regulated the activity of new adult‐born cells in the OB. Overnight CR induced c‐Fos expression in new adult‐born OB cells but not in developmentally born cells, whereas neuronal activity was absent following re‐feeding. These effects were not present in ghrelin−/− mice, suggesting that adult‐born cells are uniquely sensitive to changes in ghrelin mediated by fasting and re‐feeding. In summary, ghrelin does not promote neurogenesis in the SVZ and OB; however, new adult‐born OB cells are activated by CR in a ghrelin‐dependent manner
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