4,874 research outputs found
The role of values in collaborative consumption: insights from a product-service system for lending and borrowing in the UK
Collaborative consumption is an emerging socio-economic model based on sharing, renting, gifting, bartering, swapping, lending and borrowing. Made possible through community interaction and, increasingly, use of network technologies, these alternative and more sustainable ways of consuming have attracted growing attention for their potential to prevent new purchases, intensify the use of idle assets and promote reuse of possessions that are no longer wanted. Nonetheless, the uptake of Product- Service Systems (PSSs) that enable collaborative consumption is still very limited. This paper investigates how consumers' values can influence the acceptance, adoption and diffusion of collaborative consumption. It reviews two theoretical frameworks used to understand pro-environmental behaviour, social psychological models of behaviour and social practice theory. Coming from contrasting disciplinary perspectives, these approaches conceptualise values differently. The paper evaluates the possibility of resolving these differences through a mixed methods study. It examines values empirically through a case study of Ecomodo, a UK-based online marketplace where people can lend and borrow each other's objects, spaces and skills, and present the results of a quantitative study which identified and measured value priorities among Ecomodo users through Schwartz's Portrait Value Questionnaire. It concludes with a discussion of the role of values in relation to the introduction and scaling up of PSSs that enable collaborative consumption
Promoter targeted small RNAs induce long-term transcriptional gene silencing in human cells
Small RNAs targeted to gene promoters in human cells can mediate transcriptional gene silencing (TGS) by directing silent state epigenetic modifications to targeted loci. Many mechanistic details of this process remain poorly defined, and the ability to stably modulate gene expression in this manner has not been explored. Here we describe the mechanisms of establishment and maintenance of long-term transcriptional silencing of the human ubiquitin C gene (UbC). Sustained targeting of the UbC promoter with a small RNA for a minimum of 3 days resulted in long-term silencing which correlated with an early increase in histone methylation and a later increase in DNA methylation at the targeted locus. Transcriptional silencing of UbC required the presence of a promoter-associated RNA. The establishment and maintenance of the TGS were shown to require distinct protein factors. Argonaute 1 (Ago1), DNA methyltransferase 3a (DNMT3a) and histone deacetylase 1 (HDAC1) were required for the initiation of silencing, and DNA methyltransferase 1 (DNMT1) was necessary for maintenance. Taken together the data presented here highlight the cellular pathway with which noncoding RNAs interact to epigenetically regulate gene expression in human cells
Bispectrum speckle interferometry observations and radiative transfer modelling of the red supergiant NML Cyg: Multiple dust-shell structures evidencing previous superwind phases
(abridged) NML Cyg is a highly evolved OH/IR supergiant and supposed to be
among the most luminous supergiants in the galaxy. We present the first
diffraction limited 2.13micron observations of NML Cyg with 73mas resolution.
The speckle interferograms were obtained with the SAO 6m telescope, image
reconstruction is based on the bispectrum speckle interferometry method.
Radiative transfer calculations have been carried out to model the spectral
energy distribution, our 2.13micron visibility function, and mid-infrared
visibility functions. The observed dust shell properties do not appear to be in
accordance with single-shell models but seem to require multiple components.
Considering previous periods of enhanced mass-loss, various density
enhancements in the dust shell were taken into account. An extensive grid of
models was calculated for different locations and strenghts of such superwind
regions in the dust shell. To match the observations from the optical to the
sub-mm domain requires at least two superwind regions embedded in the shell.
The best model includes a dust shell with a temperature of 1000K at its inner
radius of 6.2Rstar, a close embedded superwind shell extending from 15.5Rstar
to 21.7Rstar with amplitude 10 (factor of density enhancement), and a far-out
density enhancement at 186Rstar with amplitude 5. The angular diameter of the
inner dust-shell rim amounts to 105mas. Within the various parts of the dust
shell, 1/r^2 density distributions could be maintained differing only in their
amplitude A. The present-day mass-loss rate was determined to be 1.2 10^-4
Msol/yr. The inner embedded superwind shell corresponds to a phase of enhanced
mass-loss which began ~59yr ago and lasted for ~18yr, and the outer superwind
region to a high mass-loss period which terminated 529yr ago.Comment: 12 pages including 13 PostScript figures, also available from
http://www.mpifr-bonn.mpg.de/div/ir-interferometry/publications.html;
accepted for publication in Astronomy & Astrophysic
Hepatocellular carcinoma
Liver cancer is the second leading cause of cancer-related deaths globally and has an incidence of approximately 850,000 new cases per year. Hepatocellular carcinoma (HCC) represents approximately 90% of all cases of primary liver cancer. The main risk factors for developing HCC are well known and include hepatitis B and C virus infection, alcohol intake and ingestion of the fungal metabolite aflatoxin B1. Additional risk factors such as non-alcoholic steatohepatitis are also emerging. Advances in the understanding of the molecular pathogenesis of HCC have led to identification of critical driver mutations; however, the most prevalent of these are not yet druggable targets. The molecular classification of HCC is not established, and the Barcelona Clinic Liver Cancer staging classification is the main clinical algorithm for the stratification of patients according to prognosis and treatment allocation. Surveillance programmes enable the detection of early-stage tumours that are amenable to curative therapies - resection, liver transplantation or local ablation. At more developed stages, only chemoembolization (for intermediate HCC) and sorafenib (for advanced HCC) have shown survival benefits. There are major unmet needs in HCC management that might be addressed through the discovery of new therapies and their combinations for use in the adjuvant setting and for intermediate- and advanced-stage disease. Moreover, biomarkers for therapy stratification, patient-tailored strategies targeting driver mutations and/or activating signalling cascades, and validated measurements of quality of life are needed. Recent failures in the testing of systemic drugs for intermediate and advanced stages have indicated a need to refine trial designs and to define novel approaches
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