368 research outputs found
Quantum Gravity in Everyday Life: General Relativity as an Effective Field Theory
This article is meant as a summary and introduction to the ideas of effective
field theory as applied to gravitational systems.
Contents:
1. Introduction
2. Effective Field Theories
3. Low-Energy Quantum Gravity
4. Explicit Quantum Calculations
5. ConclusionsComment: 56 pages, 2 figures, JHEP style, Invited review to appear in Living
Reviews of Relativit
Impact of product name and seasonal context on the sensory evaluation of a seasonally themed beverage
Information can have a powerful impact on liking, however, little is known about the effect of product name on consumer perception. Moreover, the influence of season, as a sensory relevant context, has never been investigated. The aim of this study was to investigate the effect of naming products with season evoking names and to compare responses between seasons. One hundred and fifty three consumers took part in either a summer (n=71) or winter (n=82) tasting of a drink named 'Winter Spice' or 'Refreshing Summer Berries'. Within each campaign, a cross-over design was applied and participants rated the drink for liking and sensory characteristics (check-all-that-apply). Neither the name nor the season had an impact on liking; however, both factors affected attribute description. The drink was described significantly more often as "spice", "Christmassy" and "mulled wine" when named 'Winter Spice', it was described more often as "blackcurrant" and "cherry" during the winter months.
Practical applications:
It appears possible to use product names to deliver different sensorial experiences without impacting negatively on liking providing that the names reflect adequately the product intrinsic qualities. Seasons appear to be a sensory relevant context, developing a greater understanding of the underpinning mechanisms is critical product development and marketing
SARAS 2 Constraints on Global 21 cm Signals from the Epoch of Reionization
Spectral distortions in the cosmic microwave background over the 40--200~MHz
band are imprinted by neutral hydrogen in the intergalactic medium prior to the
end of reionization. This signal, produced in the redshift range at
the rest frame wavelength of 21 cm, has not been detected yet; and poor
understanding of high redshift astrophysics results in a large uncertainty in
the expected spectrum. The SARAS~2 radiometer was purposely designed to detect
the sky-averaged 21-cm signal. The instrument, deployed at the Timbaktu
Collective (Southern India) in April--June 2017, collected 63~hr of science
data, which were examined for the presence of the cosmological 21-cm signal. In
our previous work the first-light data from SARAS~2 radiometer were analyzed
with Bayesian likelihood-ratio tests using plausible astrophysical
scenarios. In this paper we re-examine the data using an improved analysis
based on the frequentist approach and forward modeling. We show that SARAS~2
data rejects 27 models, out of which 25 are rejected at a significance
. All the rejected models share the scenario of inefficient heating
of the primordial gas by the first population of X-ray sources along with rapid
reionization
First Results on the Epoch of Reionization from First Light with SARAS 2
Long wavelength spectral distortions in the Cosmic Microwave Background
arising from the 21-cm transition in neutral Hydrogen are a key probe of Cosmic
Dawn and the Epoch of Reionization. These features may reveal the nature of the
first stars and ultra-faint galaxies that transformed the spin temperature and
ionization state of the primordial gas. SARAS~2 is a spectral radiometer
purposely designed for precision measurement of these monopole or all-sky
global 21-cm spectral distortions. We use 63~hr night time observing of the
radio background in the frequency band 110-200~MHz with the radiometer deployed
at the Timbaktu Collective in Southern India to derive likelihoods for
plausible redshifted 21-cm signals predicted by theoretical models. First light
with SARAS 2 disfavors the class of models that feature weak X-ray heating
(with ) and rapid reionization (with peak )
Malaria prevalence in Nias District, North Sumatra Province, Indonesia
BACKGROUND: The Nias district of the North Sumatra Province of Indonesia has long been known to be endemic for malaria. Following the economic crisis at the end of 1998 and the subsequent tsunami and earthquake, in December 2004 and March 2005, respectively, the malaria control programme in the area deteriorated. The present study aims to provide baseline data for the establishment of a suitable malaria control programme in the area and to analyse the frequency distribution of drug resistance alleles associated with resistance to chloroquine and sulphadoxine-pyrimethamine.\ud
METHODS: Malariometric and entomology surveys were performed in three subdistricts. Thin and thick blood smears were stained with Giemsa and examined under binocular light microscopy. Blood blots on filter paper were also prepared for isolation of parasite and host DNA to be used for molecular analysis of band 3 (SAO), pfcrt, pfmdr1, dhfr, and dhps. In addition, haemoglobin measurement was performed in the second and third surveys for the subjects less than 10 years old.\ud
RESULTS: Results of the three surveys revealed an average slide positivity rate of 8.13%, with a relatively higher rate in certain foci. Host genetic analysis, to identify the Band 3 deletion associated with Southeast Asian Ovalocytosis (SAO), revealed an overall frequency of 1.0% among the 1,484 samples examined. One hundred six Plasmodium falciparum isolates from three sub-districts were successfully analysed. Alleles of the dhfr and dhps genes associated with resistance to sulphadoxine-pyrimethamine, dhfr C59R and S108N, and dhps A437G and K540E, were present at frequencies of 52.2%, 82.5%, 1.18% and 1.18%, respectively. The pfmdr1 alleles N86Y and N1042D, putatively associated with mefloquine resistance, were present at 31.4% and 2%, respectively. All but one sample carried the pfcrt 76T allele associated with chloroquine resistance. Entomologic surveys identified three potential anopheline vectors in the area, Anopheles barbirostris, Anopheles kochi and Anopheles sundaicus.\ud
CONCLUSION: The cross sectional surveys in three different sub-districts of Nias District clearly demonstrated the presence of relatively stable endemic foci of malaria in Nias District, North Sumatra Province, Indonesia. Molecular analysis of the malaria parasite isolates collected from this area strongly indicates resistance to chloroquine and a growing threat of resistance to sulphadoxine-pyrimethamine. This situation highlights the need to develop sustainable malaria control measures through regular surveillance and proper antimalarial drug deployment
Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV
We present limits on anomalous WWZ and WW-gamma couplings from a search for
WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p
-> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron
Collider during the 1992-1995 run. The data sample corresponds to an integrated
luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling
parameters, the 95% CL limits on the CP-conserving couplings are
-0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a
form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also
presented.Comment: 11 pages, 2 figures, 2 table
Search for New Physics in e mu X Data at D0 Using Sleuth: A Quasi-Model-Independent Search Strategy for New Physics
We present a quasi-model-independent search for the physics responsible for
electroweak symmetry breaking. We define final states to be studied, and
construct a rule that identifies a set of relevant variables for any particular
final state. A new algorithm ("Sleuth") searches for regions of excess in those
variables and quantifies the significance of any detected excess. After
demonstrating the sensitivity of the method, we apply it to the semi-inclusive
channel e mu X collected in 108 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV
at the D0 experiment during 1992-1996 at the Fermilab Tevatron. We find no
evidence of new high p_T physics in this sample.Comment: 23 pages, 12 figures. Submitted to Physical Review
The Dijet Mass Spectrum and a Search for Quark Compositeness in bar{p}p Collisions at sqrt{s} = 1.8 TeV
Using the DZero detector at the 1.8 TeV pbarp Fermilab Tevatron collider, we
have measured the inclusive dijet mass spectrum in the central pseudorapidity
region |eta_jet| < 1.0 for dijet masses greater than 200 Gev/c^2. We have also
measured the ratio of spectra sigma(|eta_jet| < 0.5)/sigma(0.5 < |eta_jet| <
1.0). The order alpha_s^3 QCD predictions are in good agreement with the data
and we rule out models of quark compositeness with a contact interaction scale
< 2.4 TeV at the 95% confidence level.Comment: 11 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let
Search for High Mass Photon Pairs in p-pbar --> gamma-gamma-jet-jet Events at sqrt(s)=1.8 TeV
A search has been carried out for events in the channel p-barp --> gamma
gamma jet jet. Such a signature can characterize the production of a
non-standard Higgs boson together with a W or Z boson. We refer to this
non-standard Higgs, having standard model couplings to vector bosons but no
coupling to fermions, as a "bosonic Higgs." With the requirement of two high
transverse energy photons and two jets, the diphoton mass (m(gamma gamma))
distribution is consistent with expected background. A 90(95)% C.L. upper limit
on the cross section as a function of mass is calculated, ranging from
0.60(0.80) pb for m(gamma gamma) = 65 GeV/c^2 to 0.26(0.34) pb for m(gamma
gamma) = 150 GeV/c^2, corresponding to a 95% C.L. lower limit on the mass of a
bosonic Higgs of 78.5 GeV/c^2.Comment: 9 pages, 3 figures. Replacement has new H->gamma gamma branching
ratios and corresponding new mass limit
Zgamma Production in pbarp Collisions at sqrt(s)=1.8 TeV and Limits on Anomalous ZZgamma and Zgammagamma Couplings
We present a study of Z +gamma + X production in p-bar p collisions at
sqrt{S}=1.8 TeV from 97 (87) pb^{-1} of data collected in the eegamma
(mumugamma) decay channel with the D0 detector at Fermilab. The event yield and
kinematic characteristics are consistent with the Standard Model predictions.
We obtain limits on anomalous ZZgamma and Zgammagamma couplings for form factor
scales Lambda = 500 GeV and Lambda = 750 GeV. Combining this analysis with our
previous results yields 95% CL limits |h{Z}_{30}| < 0.36, |h{Z}_{40}| < 0.05,
|h{gamma}_{30}| < 0.37, and |h{gamma}_{40}| < 0.05 for a form factor scale
Lambda=750 GeV.Comment: 17 Pages including 2 Figures. Submitted to PR
- …