431 research outputs found
Link Prediction with Social Vector Clocks
State-of-the-art link prediction utilizes combinations of complex features
derived from network panel data. We here show that computationally less
expensive features can achieve the same performance in the common scenario in
which the data is available as a sequence of interactions. Our features are
based on social vector clocks, an adaptation of the vector-clock concept
introduced in distributed computing to social interaction networks. In fact,
our experiments suggest that by taking into account the order and spacing of
interactions, social vector clocks exploit different aspects of link formation
so that their combination with previous approaches yields the most accurate
predictor to date.Comment: 9 pages, 6 figure
A Kiloparsec-scale Molecular Wave in the Inner Galaxy: Feather of the Milky Way?
We report the discovery of a velocity coherent, kiloparsec-scale molecular structure toward the Galactic center region with an angular extent of 30° and an aspect ratio of 60:1. The kinematic distance of the CO structure ranges between 4.4 and 6.5 kpc. Analysis of the velocity data and comparison with the existing spiral arm models support that a major portion of this structure is either a subbranch of the Norma arm or an interarm giant molecular filament, likely to be a kiloparsec-scale feather (or spur) of the Milky Way, similar to those observed in nearby spiral galaxies. The filamentary cloud is at least 2.0 kpc in extent, considering the uncertainties in the kinematic distances, and it could be as long as 4 kpc. The vertical distribution of this highly elongated structure reveals a pattern similar to that of a sinusoidal wave. The exact mechanisms responsible for the origin of such a kiloparsecscale filament and its wavy morphology remains unclear. The distinct wave-like shape and its peculiar orientation makes this cloud, named as the Gangotri wave, one of the largest and most intriguing structures identified in the Milky Way
Chapter 3. Effectiveness of nature protection legislation in the European Union and the United States:the Habitats Directive and the Endangered Species Act
Dexamethasone-induced cisplatin and gemcitabine resistance in lung carcinoma samples treated ex vivo
Chemotherapy for lung cancer not only has severe side effects but frequently also exhibits limited, if any clinical effectiveness. Dexamethasone (DEX) and similar glucocorticoids (GCs) such as prednisone are often used in the clinical setting, for example, as cotreatment to prevent nausea and other symptoms. Clinical trials evaluating the impact of GCs on tumour control and patient survival of lung carcinoma have never been performed. Therefore, we isolated cancer cells from resected lung tumour specimens and treated them with cisplatin in the presence or absence of DEX. Cell number of viable and dead cells was evaluated by trypan blue exclusion and viability was measured by the MTT-assay. We found that DEX induced resistance toward cisplatin in all of 10 examined tumour samples. Similar results were found using gemcitabine as cytotoxic drug. Survival of drug-treated lung carcinoma cells in the presence of DEX was longlasting as examined 2 and 3 weeks after cisplatin treatment of a lung carcinoma cell line. These data corroborate recent in vitro and in vivo xenograft findings and rise additional concerns about the widespread combined use of DEX with antineoplastic drugs in the clinical management of patients with lung cancer
Protein expression profiles indicative for drug resistance of non-small cell lung cancer
Data obtained from multiple sources indicate that no single mechanism can explain the resistance to chemotherapy exhibited by non-small cell lung carcinomas. The multi-factorial nature of drug resistance implies that the analysis of comprising expression profiles may predict drug resistance with higher accuracy than single gene or protein expression studies. Forty cellular parameters (drug resistance proteins, proliferative, apoptotic, and angiogenic factors, products of proto-oncogenes, and suppressor genes) were evaluated mainly by immunohistochemistry in specimens of primary non-small cell lung carcinoma of 94 patients and compared with the response of the tumours to doxorubicin in vitro. The protein expression profile of non-small cell lung carcinoma was determined by hierarchical cluster analysis and clustered image mapping. The cluster analysis revealed three different resistance profiles. The frequency of each profile was different (77, 14 and 9%, respectively). In the most frequent drug resistance profile, the resistance proteins P-glycoprotein/MDR1 (MDR1, ABCB1), thymidylate-synthetase, glutathione-S-transferase-π, metallothionein, O6-methylguanine-DNA-methyltransferase and major vault protein/lung resistance-related protein were up-regulated. Microvessel density, the angiogenic factor vascular endothelial growth factor and its receptor FLT1, and ECGF1 as well were down-regulated. In addition, the proliferative factors proliferating cell nuclear antigen and cyclin A were reduced compared to the sensitive non-small cell lung carcinoma. In this resistance profile, FOS was up-regulated and NM23 down-regulated. In the second profile, only three resistance proteins were increased (glutathione-S-transferase-π, O6-methylguanine-DNA-methyltransferase, major vault protein/lung resistance-related protein). The angiogenic factors were reduced. In the third profile, only five of the resistance factors were increased (MDR1, thymidylate-synthetase, glutathione-S-transferase-π, O6-methylguanine-DNA-methyltransferase, major vault protein/lung resistance-related protein)
The SEDIGISM survey: First Data Release and overview of the Galactic structure
The SEDIGISM (Structure, Excitation and Dynamics of the Inner Galactic Interstellar Medium) survey used the APEX telescope to map 84 deg of the Galactic plane between ℓ = −60° and +31° in several molecular transitions, including CO (2 – 1) and CO (2 – 1), thus probing the moderately dense (∼10 cm) component of the interstellar medium. With an angular resolution of 30 arcsec and a typical 1σ sensitivity of 0.8–1.0 K at 0.25 km s velocity resolution, it gives access to a wide range of structures, from individual star-forming clumps to giant molecular clouds and complexes. The coverage includes a good fraction of the first and fourth Galactic quadrants, allowing us to constrain the large-scale distribution of cold molecular gas in the inner Galaxy. In this paper, we provide an updated overview of the full survey and the data reduction procedures used. We also assess the quality of these data and describe the data products that are being made publicly available as part of this First Data Release (DR1). We present integrated maps and position–velocity maps of the molecular gas and use these to investigate the correlation between the molecular gas and the large-scale structural features of the Milky Way such as the spiral arms, Galactic bar and Galactic Centre. We find that approximately 60 per cent of the molecular gas is associated with the spiral arms and these appear as strong intensity peaks in the derived Galactocentric distribution. We also find strong peaks in intensity at specific longitudes that correspond to the Galactic Centre and well-known star-forming complexes, revealing that the CO emission is concentrated in a small number of complexes rather than evenly distributed along spiral arms
SEDIGISM-ATLASGAL: Dense Gas Fraction and Star Formation Efficiency Across the Galactic Disk
By combining two surveys covering a large fraction of the molecular material in the Galactic disk we investigate the role the spiral arms play in the star formation process. We have matched clumps identified by ATLASGAL with their parental GMCs as identified by SEDIGISM, and use these giant molecular cloud (GMC) masses, the bolometric luminosities, and integrated clump masses obtained in a concurrent paper to estimate the dense gas fractions () and the instantaneous star forming efficiencies (i.e., ). We find that the molecular material associated with ATLASGAL clumps is concentrated in the spiral arms (∼60 per cent found within ±10 km s of an arm). We have searched for variations in the values of these physical parameters with respect to their proximity to the spiral arms, but find no evidence for any enhancement that might be attributable to the spiral arms. The combined results from a number of similar studies based on different surveys indicate that, while spiral-arm location plays a role in cloud formation and HI to H conversion, the subsequent star formation processes appear to depend more on local environment effects. This leads us to conclude that the enhanced star formation activity seen towards the spiral arms is the result of source crowding rather than the consequence of a any physical process
Citizenship, Justice and the Right to the Smart City
This paper provides an introduction to the smart city and engages with its idea and ideals
from a critical social science perspective. After setting out in brief the emergence of smart
cities and current key debates, we note a number of practical, political and normative
questions relating to citizenship, justice, and the public good that warrant examination. The
remainder of the paper provides an initial framing for engaging with these questions. The first
section details the dominant neoliberal conception and enactment of smart cities and how this
works to promote the interests of capital and state power and reshape governmentality. We
then detail some of the ethical issues associated with smart city technologies and initiatives.
Having set out some of the more troubling aspects of how social relations are produced
within smart cities, we then examine how citizens and citizenship have been conceived and
operationalised in the smart city to date. We then follow this with a discussion of social
justice and the smart city. In the final section, we explore the notion of the ‘right to the smart
city’ and how this might be used to recast the smart city in emancipatory and empowering
ways
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