223 research outputs found
Clouds, solar irradiance and mean surface temperature over the last century
The inter-relation of clouds, solar irradiance and surface temperature is
complex and subject to different interpretations. Here, we continue our recent
work, which related mainly to the period from 1960 to the present, back to 1900
with further, but less detailed, analysis of the last 1000 years. The last 20
years is examined especially. Attention is given to the mean surface
temperature, solar irradiance correlation, which appears to be present (with
decadal smoothing) with a 22-year period; it is stronger than the 11-year cycle
correlation with one year resolution. UV in the solar radiation is a likely
cause. Cloud data are taken from synoptic observations back to 1952 and, again,
there appears to be a correlation - with opposite phase for high and low clouds
- at the 20-30y level. Particular attention is devoted to answering the
question, 'what fraction of the observed increase in mean Global temperature
(~0.7^oC) can be attributed to solar, as distinct from man-made, effects?' We
conclude that a best estimate is 'essentially' all from 1900 to 1956 and <14%
from 1956 to the present.Comment: 10 pages, 6 figures, accepted by Journal of Atmospheric and
Solar-Terrestrial Physic
How do cities approach policy innovation and policy learning? A study of 30 policies in Northern Europe and North America
This paper reports on a study of current practice in policy transfer, and ways in which its effectiveness can be increased. A literature review identifies important factors in examining the transfer of policies. Results of interviews in eleven cities in Northern Europe and North America investigate these factors further. The principal motivations for policy transfer were strategic need and curiosity. Local officials and politicians dominated the process of initiating policy transfer, and local officials were also the leading players in transferring experience. A range of information sources are used in the search process but human interaction was the most important source of learning for two main reasons. First, there is too much information available through the Internet and the search techniques are not seen to be wholly effective in identifying the necessary information. Secondly, the information available on websites, portals and even good practice guides is not seen to be of mixed quality with risks of focussing only on successful implementation and therefore subject to some bias. Officials therefore rely on their trusted networks of peers for lessons as here they can access the ‘real implementation’ story and the unwritten lessons. Organisations which have a culture that is supportive of learning from elsewhere had strong and broad networks of external contacts and resourced their development whilst others are more insular or inward looking and reluctant to invest in policy lessons from elsewhere. Solutions to the problems identified in the evidence base are proposed
A coproduced patient and public event: An approach to developing and prioritizing ambulance performance measures
Background
Patient and Public Involvement (PPI) is recognised as an important component of high quality health
services research. PPI is integral within the Pre-hospital Outcomes for Evidence Based Evaluation
(PhOEBE) programme. The PPI event described in detail in this paper focusses on the process of
involving patients and public representatives in identifying, prioritising and refining a set of outcome
measures that can be used to support ambulance service performance measurement.
Objective
To obtain public feedback on little known, complex aspects of ambulance service performance
measurement.
Design
The event was co-designed and co-produced with the PhOEBE PPI reference group and PhOEBE
research team. The event consisted of: brief researcher-led presentations, group discussions
facilitated by the PPI reference group members and electronic voting.
Setting and participants
Data were collected from eighteen patient and public representatives who attended an event venue
in Yorkshire.
Results
The results of the PPI event showed that this interactive format and mode of delivery was an
effective method to obtain public feedback and produced a clear indication of which ambulance
performance measures were most highly favoured by event participants.
Discussion and Conclusions
The event highlighted valuable contributions the PPI reference group made to the design process,
supporting participant recruitment and facilitation of group discussions. In addition, the positive
team working experience of the event proved a catalyst for further improvements in patient and
public involvement within the PhOEBE project
On the correlation between cosmic ray intensity and cloud cover
Various aspects of the connection between cloud cover (CC) and cosmic rays
(CR) are analysed. Many features of this connection indicate that there is no
direct causal connection between low cloud cover (LCC) and CR in spite of the
evident long-term correlation between them. However, most of these features are
indirect. If only some part of the LCC is connected and varies with CR, then
its value, obtained from the joint analysis of their 11-year variations, and
averaged over the globe, should be most likely less than 20%.
The most significant argument against a causal connection of CR and LCC is
the anticorrelation between LCC and the medium cloud cover (MCC). The scenario
of the parallel influence of the solar activity on the global temperature and
CC on one side and CR on the other, which can lead to the observed
correlations, is discussed and advocated.Comment: 30 pages, 10 figures, accepted for publication in Journal of
Atmospheric and Solar-Terrestrial Physics, acknowledgements replace
The scintillation and ionization yield of liquid xenon for nuclear recoils
XENON10 is an experiment designed to directly detect particle dark matter. It
is a dual phase (liquid/gas) xenon time-projection chamber with 3D position
imaging. Particle interactions generate a primary scintillation signal (S1) and
ionization signal (S2), which are both functions of the deposited recoil energy
and the incident particle type. We present a new precision measurement of the
relative scintillation yield \leff and the absolute ionization yield Q_y, for
nuclear recoils in xenon. A dark matter particle is expected to deposit energy
by scattering from a xenon nucleus. Knowledge of \leff is therefore crucial for
establishing the energy threshold of the experiment; this in turn determines
the sensitivity to particle dark matter. Our \leff measurement is in agreement
with recent theoretical predictions above 15 keV nuclear recoil energy, and the
energy threshold of the measurement is 4 keV. A knowledge of the ionization
yield \Qy is necessary to establish the trigger threshold of the experiment.
The ionization yield \Qy is measured in two ways, both in agreement with
previous measurements and with a factor of 10 lower energy threshold.Comment: 8 pages, 9 figures. To be published in Nucl. Instrum. Methods
Determination of the Strange Quark Content of the Nucleon from a Next-to-Leading-Order QCD Analysis of Neutrino Charm Production
We present the first next-to-leading-order QCD analysis of neutrino charm
production, using a sample of 6090 - and -induced
opposite-sign dimuon events observed in the CCFR detector at the Fermilab
Tevatron. We find that the nucleon strange quark content is suppressed with
respect to the non-strange sea quarks by a factor \kappa = 0.477 \:
^{+\:0.063}_{-\:0.053}, where the error includes statistical, systematic and
QCD scale uncertainties. In contrast to previous leading order analyses, we
find that the strange sea -dependence is similar to that of the non-strange
sea, and that the measured charm quark mass, , is larger and consistent with that determined in other processes.
Further analysis finds that the difference in -distributions between
and is small. A measurement of the Cabibbo-Kobayashi-Maskawa
matrix element is also presented.
uufile containing compressed postscript files of five Figures is appended at
the end of the LaTeX source.Comment: Nevis R#150
First Observation of Coherent Production in Neutrino Nucleus Interactions with 2 GeV
The MiniBooNE experiment at Fermilab has amassed the largest sample to date
of s produced in neutral current (NC) neutrino-nucleus interactions at
low energy. This paper reports a measurement of the momentum distribution of
s produced in mineral oil (CH) and the first observation of coherent
production below 2 GeV. In the forward direction, the yield of events
observed above the expectation for resonant production is attributed primarily
to coherent production off carbon, but may also include a small contribution
from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino
flux, the sum of the NC coherent and diffractive modes is found to be (19.5
1.1 (stat) 2.5 (sys))% of all exclusive NC production at
MiniBooNE. These measurements are of immediate utility because they quantify an
important background to MiniBooNE's search for
oscillations.Comment: Submitted to Phys. Lett.
Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance
We have made a first measurement of the lepton momentum spectrum in a sample
of events enriched in neutral B's through a partial reconstruction of B0 -->
D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the
Upsilon(4S) resonance by the CLEO II detector, is compared directly to the
inclusive lepton spectrum from all Upsilon(4S) events in the same data set.
These two spectra are consistent with having the same shape above 1.5 GeV/c.
From the two spectra and two other CLEO measurements, we obtain the B0 and B+
semileptonic branching fractions, b0 and b+, their ratio, and the production
ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950
(+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57
+- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes,
tau+/tau0.Comment: 14 page, postscript file also available at
http://w4.lns.cornell.edu/public/CLN
Measurement of the Mass Splittings between the States
We present new measurements of photon energies and branching fractions for
the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the
chi_b states are determined from the measured radiative photon energies. The
ratio of mass splittings between the chi_b substates,
r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information
on the nature of the bbbar confining potential. We find
r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world
average, but more consistent with the theoretical expectation that r(1P)<r(2P);
i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than
for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
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