5,089 research outputs found
From everyday conversation to political action: Talking austerity in online ‘third spaces’
Taking forward a new agenda for online political deliberation – the study of everyday political talk in non-political, online ‘third spaces’ – this article examines the dynamics of political talk across three general interest UK-based online forums. The quantitative analysis found that discussions about austerity were just as likely to emerge from non-political discussions as they were ones that began as ‘political’, demonstrating the links people made between everyday experiences and public policy. Our qualitative analysis represents the first real attempt to analyse political actions within third spaces, with some striking outcomes. Over half of all political discussions led to at least one political action (with significant variation between forums). The findings demonstrate that while such third spaces remain concerned with the preoccupations of everyday life, they can and do perform a role of mobilizing agent towards political participation
Disruption of a Proto-Planetary Disk by the Black Hole at the Milky Way Centre
Recently, an ionized cloud of gas was discovered plunging toward the
supermassive black hole, SgrA*, at the centre of the Milky Way. The cloud is
being tidally disrupted along its path to closest approach at ~3100
Schwarzschild radii from the black hole. Here, we show that the observed
properties of this cloud of gas can naturally be produced by a proto-planetary
disk surrounding a low-mass star, which was scattered from the observed ring of
young stars orbiting SgrA*. As the young star approaches the black hole, its
disk experiences both photo-evaporation and tidal disruption, producing a
cloud. Our model implies that planets form in the Galactic centre, and that
tidal debris from proto-planetary disks can flag low mass stars which are
otherwise too faint to be detected.Comment: Accepted to Nature Communications; new Figure 4b provides predicted
Br-gamma emission as a function of tim
The sign problem across the QCD phase transition
The average phase factor of the QCD fermion determinant signals the strength
of the QCD sign problem. We compute the average phase factor as a function of
temperature and baryon chemical potential using a two-flavor NJL model. This
allows us to study the strength of the sign problem at and above the chiral
transition. It is discussed how the anomaly affects the sign problem.
Finally, we study the interplay between the sign problem and the endpoint of
the chiral transition.Comment: 9 pages and 9 fig
An Anti-Human ICAM-1 Antibody Inhibits Rhinovirus-Induced Exacerbations of Lung Inflammation
Human rhinoviruses (HRV) cause the majority of common colds and acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD). Effective therapies are urgently needed, but no licensed treatments or vaccines currently exist. Of the 100 identified serotypes, ∼90% bind domain 1 of human intercellular adhesion molecule-1 (ICAM-1) as their cellular receptor, making this an attractive target for development of therapies; however, ICAM-1 domain 1 is also required for host defence and regulation of cell trafficking, principally via its major ligand LFA-1. Using a mouse anti-human ICAM-1 antibody (14C11) that specifically binds domain 1 of human ICAM-1, we show that 14C11 administered topically or systemically prevented entry of two major groups of rhinoviruses, HRV16 and HRV14, and reduced cellular inflammation, pro-inflammatory cytokine induction and virus load in vivo. 14C11 also reduced cellular inflammation and Th2 cytokine/chemokine production in a model of major group HRV-induced asthma exacerbation. Interestingly, 14C11 did not prevent cell adhesion via human ICAM-1/LFA-1 interactions in vitro, suggesting the epitope targeted by 14C11 was specific for viral entry. Thus a human ICAM-1 domain-1-specific antibody can prevent major group HRV entry and induction of airway inflammation in vivo
Mobility promotes and jeopardizes biodiversity in rock-paper-scissors games
Biodiversity is essential to the viability of ecological systems. Species
diversity in ecosystems is promoted by cyclic, non-hierarchical interactions
among competing populations. Such non-transitive relations lead to an evolution
with central features represented by the `rock-paper-scissors' game, where rock
crushes scissors, scissors cut paper, and paper wraps rock. In combination with
spatial dispersal of static populations, this type of competition results in
the stable coexistence of all species and the long-term maintenance of
biodiversity. However, population mobility is a central feature of real
ecosystems: animals migrate, bacteria run and tumble. Here, we observe a
critical influence of mobility on species diversity. When mobility exceeds a
certain value, biodiversity is jeopardized and lost. In contrast, below this
critical threshold all subpopulations coexist and an entanglement of travelling
spiral waves forms in the course of temporal evolution. We establish that this
phenomenon is robust, it does not depend on the details of cyclic competition
or spatial environment. These findings have important implications for
maintenance and evolution of ecological systems and are relevant for the
formation and propagation of patterns in excitable media, such as chemical
kinetics or epidemic outbreaks.Comment: Final submitted version; the printed version can be found at
http://dx.doi.org/10.1038/nature06095 Supplementary movies are available at
http://www.theorie.physik.uni-muenchen.de/lsfrey/images_content/movie1.AVI
and
http://www.theorie.physik.uni-muenchen.de/lsfrey/images_content/movie2.AV
Belowground DNA-based techniques: untangling the network of plant root interactions
Contains fulltext :
91591.pdf (publisher's version ) (Closed access)7 p
Pathological Features of Breast Cancer seen in Northwestern Tanzania: A Nine Years Retrospective Study.
Breast cancer is more common in Western Countries compared to African populations. However in African population, it appears that the disease tends to be more aggressive and occurring at a relatively young age at the time of presentation. The aim of this study was to describe the trend of Breast Cancer in Northwestern Tanzania. This was a retrospective study which involved all cases of breast cancer diagnosed histologically at Bugando Medical Center from 2002 to 2010. Histological results and slides were retrieved from the records in the Pathology department, clinical information and demographic data for patients were retrieved from surgical wards and department of medical records. Histology slides were re-evaluated for the histological type, grade (By modified Bloom-Richardson score), and presence of necrosis and skin involvement. Data was entered and analyzed by SPSS computer software version 15. There were 328 patients histologically confirmed to have breast cancer, the mean age at diagnosis was 48.7 years (+/- 13.1). About half of the patients (52.4%) were below 46 years of age, and this group of patients had significantly higher tendency for lymph node metastasis (p = 0.012). The tumor size ranged from 1 cm to 18 cm in diameter with average (mean) of 5.5 cm (+/- 2.5), and median size of 6 cm. Size of the tumor (above 6 cm in diameter) and presence of necrosis within the tumor was significantly associated with high rate of lymph node metastasis (p = 0.000). Of all patients, 64% were at clinical stage III (specifically IIIB) and 70.4% had lymph node metastasis at the time of diagnosis. Only 4.3% of the patients were in clinical stage I at the time of diagnosis. Majority of the patients had invasive ductal carcinoma (91.5%) followed by mucinous carcinoma (5.2%), Invasive lobular carcinoma (3%) and in situ ductal carcinoma (0.3%). In all patients, 185 (56.4%) had tumor with histological grade 3. Breast cancer in this region show a trend towards relative young age at diagnosis with advanced stage at diagnosis and high rate of lymph node metastasis. Poor Referral system, lack of screening programs and natural aggressive biological behavior of tumor may contribute to advanced disease at the time of diagnosis
Zircon ages in granulite facies rocks: decoupling from geochemistry above 850 °C?
Granulite facies rocks frequently show a large spread in their zircon ages, the interpretation of which raises questions: Has the isotopic system been disturbed? By what process(es) and conditions did the alteration occur? Can the dates be regarded as real ages, reflecting several growth episodes? Furthermore, under some circumstances of (ultra-)high-temperature metamorphism, decoupling of zircon U–Pb dates from their trace element geochemistry has been reported. Understanding these processes is crucial to help interpret such dates in the context of the P–T history. Our study presents evidence for decoupling in zircon from the highest grade metapelites (> 850 °C) taken along a continuous high-temperature metamorphic field gradient in the Ivrea Zone (NW Italy). These rocks represent a well-characterised segment of Permian lower continental crust with a protracted high-temperature history. Cathodoluminescence images reveal that zircons in the mid-amphibolite facies preserve mainly detrital cores with narrow overgrowths. In the upper amphibolite and granulite facies, preserved detrital cores decrease and metamorphic zircon increases in quantity. Across all samples we document a sequence of four rim generations based on textures. U–Pb dates, Th/U ratios and Ti-in-zircon concentrations show an essentially continuous evolution with increasing metamorphic grade, except in the samples from the granulite facies, which display significant scatter in age and chemistry. We associate the observed decoupling of zircon systematics in high-grade non-metamict zircon with disturbance processes related to differences in behaviour of non-formula elements (i.e. Pb, Th, U, Ti) at high-temperature conditions, notably differences in compatibility within the crystal structure
Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions
The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions
Benefits and risks of the hormetic effects of dietary isothiocyanates on cancer prevention
The isothiocyanate (ITC) sulforaphane (SFN) was shown at low levels (1-5 µM) to promote cell proliferation to 120-143% of the controls in a number of human cell lines, whilst at high levels (10-40 µM) it inhibited such cell proliferation. Similar dose responses were observed for cell migration, i.e. SFN at 2.5 µM increased cell migration in bladder cancer T24 cells to 128% whilst high levels inhibited cell migration. This hormetic action was also found in an angiogenesis assay where SFN at 2.5 µM promoted endothelial tube formation (118% of the control), whereas at 10-20 µM it caused significant inhibition. The precise mechanism by which SFN influences promotion of cell growth and migration is not known, but probably involves activation of autophagy since an autophagy inhibitor, 3-methyladenine, abolished the effect of SFN on cell migration. Moreover, low doses of SFN offered a protective effect against free-radical mediated cell death, an effect that was enhanced by co-treatment with selenium. These results suggest that SFN may either prevent or promote tumour cell growth depending on the dose and the nature of the target cells. In normal cells, the promotion of cell growth may be of benefit, but in transformed or cancer cells it may be an undesirable risk factor. In summary, ITCs have a biphasic effect on cell growth and migration. The benefits and risks of ITCs are not only determined by the doses, but are affected by interactions with Se and the measured endpoint
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