5,458 research outputs found
Chiral perturbation theory in a magnetic background - finite-temperature effects
We consider chiral perturbation theory for SU(2) at finite temperature in
a constant magnetic background . We compute the thermal mass of the pions
and the pion decay constant to leading order in chiral perturbation theory in
the presence of the magnetic field. The magnetic field gives rise to a
splitting between and as well as between
and . We also calculate the free energy and the
quark condensate to next-to-leading order in chiral perturbation theory. Both
the pion decay constants and the quark condensate are decreasing slower as a
function of temperature as compared to the case with vanishing magnetic field.
The latter result suggests that the critical temperature for the chiral
transition is larger in the presence of a constant magnetic field. The increase
of as a function of is in agreement with most model calculations but
in disagreement with recent lattice calculations.Comment: 24 pages and 9 fig
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
Aplica??o de prot?tipo de telhado verde para a avalia??o do escoamento superficial e aproveitamento da ?gua para fins n?o pot?veis
Due to the great urban expansion in Brazil, the areas of vegetation are being removed for the construction of roads, buildings, industries among others. This ends up decreasing the permeable areas in the cities, which can make them more vulnerable to flooding, especially in periods of intense rains. A sustainable alternative for the mitigation of the impacts caused by the waterproofing of the soils, is the implementation of green roofs. This technique, beyond acting in the cushioning of rainwater flow, can better the thermal comfort in the place, reduce noise pollution, retain atmospheric pollutants, among other benefits. Therefore, the objective of this work was to evaluate the rainwater retention efficiency of a green roof prototype, comparing it with a conventional roof prototype, both located in Cerro Largo - RS. Besides that, were analyzed in the laboratory of the UFFS, some parameters of quality of the water drained in the prototypes, to evaluate the possible non-potable reuse of these waters. 16 rainy events were monitored between September 17 and November 4, 2018. The rainfall data were obtained through the meteorological station located on the UFFS campus of Cerro Largo. The retention capacity of the green roof was satisfactory, with an average value of 51% rainwater runoff.Devido ? grande expans?o urbana no Brasil, as ?reas de vegeta??o est?o sendo removidas para a constru??o de estradas, pr?dios, ind?strias entre outros. Isto acaba diminuindo as ?reas perme?veis nas cidades, o que pode tornar as mesmas mais vulner?veis a enchentes, principalmente em per?odos de chuvas intensas. Uma alternativa sustent?vel para a mitiga??o dos impactos causados pela impermeabiliza??o dos solos, ? a implementa??o de telhados verdes. Essa t?cnica al?m de atuar no amortecimento do escoamento das ?guas pluviais, pode melhorar o conforto t?rmico no local, reduzir a polui??o sonora, reter poluentes atmosf?ricos, entre outros benef?cios. Sendo assim, este trabalho teve o objetivo de avaliar a efici?ncia na reten??o da ?gua da chuva de um prot?tipo de telhado verde, comparando-o com um prot?tipo de telhado convencional, ambos localizados em Cerro Largo ? RS. Al?m disso, foram analisados no laborat?rio da UFFS, alguns par?metros de qualidade da ?gua escoada nos prot?tipos, para avaliar o poss?vel reuso n?o pot?vel dessas ?guas. Foram monitorados 16 eventos chuvosos entre 17 de setembro e 4 de novembro de 2018. Os dados referentes ?s chuvas foram obtidos atrav?s da esta??o meteorol?gica localizada no campus da UFFS de Cerro Largo. A capacidade de reten??o do telhado verde mostrou-se satisfat?ria, com um valor m?dio de 51% de escoamento das ?guas pluviais
an individual participant data meta-analysis
Background The impact of neuraminidase inhibitors (NAIs) on influenza-related
pneumonia (IRP) is not established. Our objective was to investigate the
association between NAI treatment and IRP incidence and outcomes in patients
hospitalised with A(H1N1)pdm09 virus infection. Methods A worldwide meta-
analysis of individual participant data from 20 634 hospitalised patients with
laboratory-confirmed A(H1N1)pdm09 (n = 20 021) or clinically diagnosed (n =
613) ‘pandemic influenza’. The primary outcome was radiologically confirmed
IRP. Odds ratios (OR) were estimated using generalised linear mixed modelling,
adjusting for NAI treatment propensity, antibiotics and corticosteroids.
Results Of 20 634 included participants, 5978 (29·0%) had IRP; conversely,
3349 (16·2%) had confirmed the absence of radiographic pneumonia (the
comparator). Early NAI treatment (within 2 days of symptom onset) versus no
NAI was not significantly associated with IRP [adj. OR 0·83 (95% CI 0·64–1·06;
P = 0·136)]. Among the 5978 patients with IRP, early NAI treatment versus none
did not impact on mortality [adj. OR = 0·72 (0·44–1·17; P = 0·180)] or
likelihood of requiring ventilatory support [adj. OR = 1·17 (0·71–1·92; P =
0·537)], but early treatment versus later significantly reduced mortality
[adj. OR = 0·70 (0·55–0·88; P = 0·003)] and likelihood of requiring
ventilatory support [adj. OR = 0·68 (0·54–0·85; P = 0·001)]. Conclusions Early
NAI treatment of patients hospitalised with A(H1N1)pdm09 virus infection
versus no treatment did not reduce the likelihood of IRP. However, in patients
who developed IRP, early NAI treatment versus later reduced the likelihood of
mortality and needing ventilatory support
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Corporate philanthropy through the lens of ethical subjectivity
The dynamic organisational processes in businesses dilute the boundaries between the individual, organisational, and societal drivers of corporate philanthropy. This creates a complex framework in which charitable project selection occurs. Using the example of European tour operators, this study investigates the mechanisms through which companies invest in charitable projects in overseas destinations. Inextricably linked to this is the increasing contestation by local communities as to how they are able to engage effectively with tourism in order to realise the benefits tourism development can bring. This research furthers such debates by exploring the processes through which tour operators facilitate community development through charitable giving. Findings show, with no formal frameworks in existence, project selection depends upon emergent strategies that connect the professional with the personal, with trust being positioned as a central driver of these informal processes. Discretionary responsibilities are reworked through business leaders’ commitment to responsible business practises and the ethical subjectivity guiding these processes
Influence of the different “patient global assessment” formulations on disease activity score by different indices in rheumatoid arthritis
© 2018, International League of Associations for Rheumatology (ILAR). Patient global assessment (PGA) is included in almost all rheumatoid arthritis (RA) composite disease activity indices and definitions of remission. However, different PGA formulations exist and are used interchangeably in research and clinical practice. We investigated how five different PGA formulations used in four disease indices affect the remission rates. This was an ancillary analysis of data from a cross-sectional study in patients with RA. The data comprised the following: 28-joint counts, C-reactive protein, and five PGA formulations. Remission rate variation was assessed using five PGA formulations in each index (ACR/EULAR Boolean, CDAI, SDAI, and DAS28-CRP). PGA agreement was assessed by the following: Pearson’s correlation; Bland-Altman plots; paired samples t test; and establishing the proportion of patients who scored (i) all formulations within an interval of 20mm and (ii) each formulation ≤ 10mm. This analysis included 191 patients. PGA formulations presented good correlations (≥ 0.65), but Bland-Altman plots showed clinically significant differences, which were statistically confirmed by comparison of means. Just over a half (51.8%) of patients scored all PGA formulations within a 20-mm interval. The proportion of those scoring ≤ 10mm varied from 11.5 to 16.2%. When different formulations of PGA were used in each index, remission differences of up to 4.7, 4.7, 6.3, and 5.2% were observed. When formulations were used in their respective indices, as validated, the remission rates were similar (13.1, 13.6, 14.1, and 18.3%). Using PGA formulations interchangeably may have implications in the assessment of disease activity and in the attainment of remission, and this can impact upon management decisions
Search for the production of dark matter in association with top-quark pairs in the single-lepton final state in proton-proton collisions at √s=8 TeV
Peer reviewe
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