632 research outputs found
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Are you talking to me? An analysis of journalism conversation on social media
Social media has become a key medium for discussion and dissemination of news stories, fuelled by the low barrier to entry and the ease of interaction. News stories may be propagated through these networks either by official news organisation accounts, by individual journalists or by members of the public, through link sharing, endorsing or commenting. This preliminary research aims to show how computational analysis of large-scale data-sets allows us to investigate the means by which news stories are spread through social media, and how the conversation around them is shaped by journalists and news organisations. Through the capture of more than 11 million tweets relating to 2303 Twitter accounts connected to journalism and news organisations, we are able to analyse the conversation within and around journalism, examining who spreads information about news articles and who interacts in the discussion around them. Capturing the tweets of news organisations and journalists and the replies and retweets of these micro-blogs allows us to build a rich picture of interaction around news media
Experiences of cervical screening and barriers to participation in the context of an organised programme: a systematic review and thematic synthesis
OBJECTIVE: As uptake of cervical screening continues to decline, this systematic review synthesises the qualitative literature on women's perceptions and experiences of cervical screening in the context of an organised call-recall programme, in order to understand the barriers to informed uptake. METHODS: We searched nine databases for English language peer-reviewed publications reporting on qualitative data from screening-eligible women, exploring barriers to cervical screening in countries that offer a nationally organised call-recall programme. Evidence was integrated using thematic synthesis. RESULTS: Thirty-nine papers from the UK, Australia, Sweden and Korea were included. The majority of participants had attended screening at least once. Two broad themes were identified: (a) should I go for screening? and (b) screening is a big deal. In considering whether to attend, women discussed the personal relevance and value of screening. Women who had previously attended described how it was a big deal, physically and emotionally, and the varied threats that screening presents. Practical barriers affected whether women translated screening intentions into action. CONCLUSIONS: The variation in women's understanding and perceptions of cervical screening suggests that interventions tailored to decisional stage may be of value in increasing engagement with the invitation and uptake of screening in those who wish to take part. There is also a need for further research with women who have never attended screening, especially those who remain unaware or unengaged, as their perspectives are lacking in the existing literature. © 2016 The Authors. Psycho-Oncology Published by John Wiley & Sons Ltd
e-Social Science and Evidence-Based Policy Assessment : Challenges and Solutions
Peer reviewedPreprin
Transport spectroscopy of an impurity spin in a carbon nanotube double quantum dot.
We make use of spin selection rules to investigate the electron spin system of a carbon nanotube double quantum dot. Measurements of the electron transport as a function of the magnetic field and energy detuning between the quantum dots reveal an intricate pattern of the spin state evolution. We demonstrate that the complete set of measurements can be understood by taking into account the interplay between spin-orbit interaction and a single impurity spin coupled to the double dot. The detection and tunability of this coupling are important for quantum manipulation in carbon nanotubes
Is aging raw cattle urine efficient for sampling Anopheles arabiensis Patton?
Background: To ensure sustainable routine surveillance of mosquito vectors, simple, effective and ethically acceptable tools are required. As a part of that, we evaluated the efficiency of resting boxes baited with fresh and aging cattle urine for indoor and outdoor sampling of An. arabiensis in the lower Moshi rice irrigation schemes. Methods: A cattle urine treatment and re-treatment schedule was used, including a box with a piece of cloth retreated with urine daily, and once after 3 and 7 day. Resting box with piece of black cloth not treated with urine was used as a control. Each treatment was made in pair for indoor and outdoor sampling. A 4 by 4 Latin square design was used to achieve equal rotation of each of the four treatments across the experimental houses. Sampling was done over a period of 6 months, once per week. Results: A total of 7871 mosquitoes were collected throughout the study period. 49.8% of the mosquitoes were collected from resting box treated with urine daily; 21.6% and 20.0% were from boxes treated 3 and 7 days respectively. Only 8.6% were from untreated resting box (control). The proportion collected indoors was similar to 2 folds greater than the outdoor. Of all mosquitoes, 12.3% were unfed, 4.1% full fed, 34.2% semi-gravid and 49.4% gravid. Conclusion: Fresh and decaying cattle urine odour baited resting boxes offer an alternative tool for sampling particularly semi-gravid and gravid An. arabiensis. Evaluation in low density seasons of An. arabiensis in different ecological settings remains necessary. This sampling method may be standardized for replacing human landing catch
Nanoscale spin rectifiers controlled by the Stark effect
The control of orbital and spin state of single electrons is a key ingredient
for quantum information processing, novel detection schemes, and, more
generally, is of much relevance for spintronics. Coulomb and spin blockade (SB)
in double quantum dots (DQDs) enable advanced single-spin operations that would
be available even for room-temperature applications for sufficiently small
devices. To date, however, spin operations in DQDs were observed at sub-Kelvin
temperatures, a key reason being that scaling a DQD system while retaining an
independent field-effect control on the individual dots is very challenging.
Here we show that quantum-confined Stark effect allows an independent
addressing of two dots only 5 nm apart with no need for aligned nanometer-size
local gating. We thus demonstrate a scalable method to fully control a DQD
device, regardless of its physical size. In the present implementation we show
InAs/InP nanowire (NW) DQDs that display an experimentally detectable SB up to
10 K. We also report and discuss an unexpected re-entrant SB lifting as a
function magnetic-field intensity
Giga-Hertz quantized charge pumping in bottom gate defined InAs nanowire quantum dots
Semiconducting nanowires (NWs) are a versatile, highly tunable material
platform at the heart of many new developments in nanoscale and quantum
physics. Here, we demonstrate charge pumping, i.e., the controlled transport of
individual electrons through an InAs NW quantum dot (QD) device at frequencies
up to GHz. The QD is induced electrostatically in the NW by a series of
local bottom gates in a state of the art device geometry. A periodic modulation
of a single gate is enough to obtain a dc current proportional to the frequency
of the modulation. The dc bias, the modulation amplitude and the gate voltages
on the local gates can be used to control the number of charges conveyed per
cycle. Charge pumping in InAs NWs is relevant not only in metrology as a
current standard, but also opens up the opportunity to investigate a variety of
exotic states of matter, e.g. Majorana modes, by single electron spectroscopy
and correlation experiments.Comment: 21 page
Dispersively detected Pauli Spin-Blockade in a Silicon Nanowire Field-Effect Transistor
We report the dispersive readout of the spin state of a double quantum dot
formed at the corner states of a silicon nanowire field-effect transistor. Two
face-to-face top-gate electrodes allow us to independently tune the charge
occupation of the quantum dot system down to the few-electron limit. We measure
the charge stability of the double quantum dot in DC transport as well as
dispersively via in-situ gate-based radio frequency reflectometry, where one
top-gate electrode is connected to a resonator. The latter removes the need for
external charge sensors in quantum computing architectures and provides a
compact way to readout the dispersive shift caused by changes in the quantum
capacitance during interdot charge transitions. Here, we observe Pauli
spin-blockade in the high-frequency response of the circuit at finite magnetic
fields between singlet and triplet states. The blockade is lifted at higher
magnetic fields when intra-dot triplet states become the ground state
configuration. A lineshape analysis of the dispersive phase shift reveals
furthermore an intradot valley-orbit splitting of 145 eV.
Our results open up the possibility to operate compact CMOS technology as a
singlet-triplet qubit and make split-gate silicon nanowire architectures an
ideal candidate for the study of spin dynamics
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