•An extension of social contact from Airbnb users’ perspectives.•Identify the key attributes of where tourists can co-create their travel experience with different participating groups.•Propose a ...social contact model for Airbnb guests.
Emerging Airbnb accommodations provide a unique sharing economy platform where tourists can co-create their travel experiences with different participating groups. However, limited research has been conducted to understand the social contact of guests in the Airbnb accommodation. This study explores the social contact of Airbnb guests during their stay and identifies three types of contact during such stay, namely guest–host, guest–community, and guest–guest contacts. In each contact, the contact activities, intensity, and impacts, as well as attitude toward contact are discussed. A social contact model for Airbnb guests is then established. Theoretical and practical implications are provided accordingly.
The coherent photoproduction of J/ψ and ψ' mesons was measured in ultra-peripheral Pb–Pb collisions at a center-of-mass energy $\sqrt{s_{\mathrm {NN}}}~=~5.02$ TeV with the ALICE detector. Charmonia ...are detected in the central rapidity region for events where the hadronic interactions are strongly suppressed. The J/ψ is reconstructed using the dilepton (l+l-) and proton–antiproton decay channels, while for the ψ' the dilepton and the l+l-π+π- decay channels are studied. The analysis is based on an event sample corresponding to an integrated luminosity of about 233 μb-1. The results are compared with theoretical models for coherent J/ψ and ψ' photoproduction. The coherent cross section is found to be in a good agreement with models incorporating moderate nuclear gluon shadowing of about 0.64 at a Bjorken-x of around 6×10-4, such as the EPS09 parametrization, however none of the models is able to fully describe the rapidity dependence of the coherent J/ψ cross section including ALICE measurements at forward rapidity. The ratio of ψ' to J/ψ coherent photoproduction cross sections was also measured and found to be consistent with the one for photoproduction off protons.
Type 2 diabetes (T2DM), hypertension and kidney dysfunction are known risk factors for cardiovascular disease, but their combined effect on carotid plaque remains uncertain. This study aims to assess ...the associations between T2DM, hypertension, kidney dysfunction and carotid plaque, and further explore the combined effect of three diseases.
We conducted a cross-sectional analysis among 3,815 community-dwelling adults in a Chinese atherosclerosis cohort. Estimated glomerular filtration rate (eGFR), hypertension and T2DM were evaluated as risk factors for carotid plaque. The presence, number and total area of carotid plaques were also assessed. Using logistic model, mutinomial logistic model and generalized linear regression model, the relationship between risk factors and carotid plaque was examined.
T2DM, hypertension, decreased GFR, and, inversely, eGFR, were independently associated with the presence, number and total area of carotid plaque. Stratified analysis by T2DM and hypertension showed T2DM attenuated the association between eGFR change and carotid plaque. There was a cumulative relationship between three risk factors and carotid plaque burden. The OR for the number of plaques was 1.0 (reference), 1.55 to 2.03, 1.94 to 3.14, and 3.69 (all
<0.05), respectively, for individuals with none, one, two, and three risk factors. Likewise, combining three risk factors was associated with greater increase in total plaque area (
, 20.63; 95% CI, 14.04-27.22).
The coexistence of decreased GFR, diabetes and hypertension is associated with increased risk of carotid plaque, and these comorbidities may contribute additively to the development of plaque.
Abstract
The coherent photoproduction of
$$\mathrm{J}/\psi $$
J
/
ψ
and
$${\uppsi '}$$
ψ
′
mesons was measured in ultra-peripheral Pb–Pb collisions at a center-of-mass energy
$$\sqrt{s_{\mathrm ...{NN}}}~=~5.02$$
s
NN
=
5.02
TeV with the ALICE detector. Charmonia are detected in the central rapidity region for events where the hadronic interactions are strongly suppressed. The
$$\mathrm{J}/\psi $$
J
/
ψ
is reconstructed using the dilepton (
$$l^{+} l^{-}$$
l
+
l
-
) and proton–antiproton decay channels, while for the
$${\uppsi '}$$
ψ
′
the dilepton and the
$$l^{+} l^{-} \pi ^{+} \pi ^{-}$$
l
+
l
-
π
+
π
-
decay channels are studied. The analysis is based on an event sample corresponding to an integrated luminosity of about 233
$$\mu {\mathrm{b}}^{-1}$$
μ
b
-
1
. The results are compared with theoretical models for coherent
$$\mathrm{J}/\psi $$
J
/
ψ
and
$${\uppsi '}$$
ψ
′
photoproduction. The coherent cross section is found to be in a good agreement with models incorporating moderate nuclear gluon shadowing of about 0.64 at a Bjorken-
x
of around
$$6\times 10^{-4}$$
6
×
10
-
4
, such as the EPS09 parametrization, however none of the models is able to fully describe the rapidity dependence of the coherent
$$\mathrm{J}/\psi $$
J
/
ψ
cross section including ALICE measurements at forward rapidity. The ratio of
$${\uppsi '}$$
ψ
′
to
$$\mathrm{J}/\psi $$
J
/
ψ
coherent photoproduction cross sections was also measured and found to be consistent with the one for photoproduction off protons.
The elliptic and triangular flow coefficients v 2 and v 3 of prompt D 0 , D + , and D * + mesons were measured at midrapidity ( | y | < 0.8 ) in Pb–Pb collisions at the centre-of-mass energy per ...nucleon pair of s NN = 5.02 TeV with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays in the transverse momentum interval 1 < p T < 36 GeV / c in central (0–10%) and semi-central (30–50%) collisions. Compared to pions, protons, and J / ψ mesons, the average D-meson v n harmonics are compatible within uncertainties with a mass hierarchy for p T ≲ 3 GeV / c , and are similar to those of charged pions for higher p T . The coupling of the charm quark to the light quarks in the underlying medium is further investigated with the application of the event-shape engineering (ESE) technique to the D-meson v 2 and p T -differential yields. The D-meson v 2 is correlated with average bulk elliptic flow in both central and semi-central collisions. Within the current precision, the ratios of per-event D-meson yields in the ESE-selected and unbiased samples are found to be compatible with unity. All the measurements are found to be reasonably well described by theoretical calculations including the effects of charm-quark transport and the recombination of charm quarks with light quarks in a hydrodynamically expanding medium.
The inclusive J/ψ elliptic (v2) and triangular (v3) flow coefficients measured at forward rapidity (2.5 < y < 4) and the v2 measured at midrapidity (|y| < 0.9) in Pb-Pb collisions at $$ ...\sqrt{s_{\mathrm{NN}}} $$ s NN = 5.02 TeV using the ALICE detector at the LHC are reported. The entire Pb-Pb data sample collected during Run 2 is employed, amounting to an integrated luminosity of 750 μb-1 at forward rapidity and 93 μb-1 at midrapidity. The results are obtained using the scalar product method and are reported as a function of transverse momentum pT and collision centrality. At midrapidity, the J/ψ v2 is in agreement with the forward rapidity measurement. The centrality averaged results indicate a positive J/ψ v3 with a significance of more than 5σ at forward rapidity in the pT range 2 < pT< 5 GeV/c. The forward rapidity v2, v3, and v3/v2 results at low and intermediate pT (pT ≲ 8 GeV/c) exhibit a mass hierarchy when compared to pions and D mesons, while converging into a species-independent curve at higher pT. At low and intermediate pT, the results could be interpreted in terms of a later thermalization of charm quarks compared to light quarks, while at high pT, path-length dependent effects seem to dominate. The J/ψ v2 measurements are further compared to a microscopic transport model calculation. Using a simplified extension of the quark scaling approach involving both light and charm quark flow components, it is shown that the D-meson vn measurements can be described based on those for charged pions and J/ψ flow.
A
bstract
The inclusive J/
ψ
elliptic (
v
2
) and triangular (
v
3
) flow coefficients measured at forward rapidity (2
.
5
< y <
4) and the
v
2
measured at midrapidity (|
y
|
<
0
.
9) in Pb-Pb ...collisions at
$$ \sqrt{s_{\mathrm{NN}}} $$
s
NN
= 5
.
02 TeV using the ALICE detector at the LHC are reported. The entire Pb-Pb data sample collected during Run 2 is employed, amounting to an integrated luminosity of 750
μ
b
−
1
at forward rapidity and 93
μ
b
−
1
at midrapidity. The results are obtained using the scalar product method and are reported as a function of transverse momentum
p
T
and collision centrality. At midrapidity, the J/
ψ v
2
is in agreement with the forward rapidity measurement. The centrality averaged results indicate a positive J/
ψ v
3
with a significance of more than 5
σ
at forward rapidity in the
p
T
range 2
< p
T
<
5 GeV/
c
. The forward rapidity
v
2
,
v
3
, and
v
3
/v
2
results at low and intermediate
p
T
(
p
T
≲ 8 GeV/
c
) exhibit a mass hierarchy when compared to pions and D mesons, while converging into a species-independent curve at higher
p
T
. At low and intermediate
p
T
, the results could be interpreted in terms of a later thermalization of charm quarks compared to light quarks, while at high
p
T
, path-length dependent effects seem to dominate. The J/
ψ v
2
measurements are further compared to a microscopic transport model calculation. Using a simplified extension of the quark scaling approach involving both light and charm quark flow components, it is shown that the D-meson
v
n
measurements can be described based on those for charged pions and J/
ψ
flow.
A
bstract
Inclusive J
/ψ
yields and average transverse momenta in p-Pb collisions at a center-of-mass energy per nucleon pair
$$ \sqrt{s_{\mathrm{NN}}} $$
s
NN
= 8
.
16 TeV are measured as a function ...of the charged-particle pseudorapidity density with ALICE. The J
/ψ
mesons are reconstructed at forward (2
.
03
< y
cms
<
3
.
53) and backward (
−
4
.
46
< y
cms
< −
2
.
96) center-of-mass rapidity in their dimuon decay channel while the charged-particle pseudorapidity density is measured around midrapidity. The J
/ψ
yields at forward and backward rapidity normalized to their respective average values increase with the normalized charged-particle pseudorapidity density, the former showing a weaker increase than the latter. The normalized average transverse momenta at forward and backward rapidity manifest a steady increase from low to high charged-particle pseudorapidity density with a saturation beyond the average value.
A
bstract
Systematic studies of charge-dependent two- and three-particle correlations in Pb-Pb collisions at
$$ \sqrt{s_{\mathrm{NN}}} $$
s
NN
= 2.76 and 5.02 TeV used to probe the Chiral Magnetic ...Effect (CME) are presented. These measurements are performed for charged particles in the pseudorapidity (
η
) and transverse momentum (
p
T
) ranges |
η
|
<
0
.
8 and 0
.
2
< p
T
<
5 GeV/
c
. A significant charge-dependent signal that becomes more pronounced for peripheral collisions is reported for the CME-sensitive correlators
γ
1, 1
= 〈cos(
φ
α
+
φ
β
− 2Ψ
2
)〉 and
γ
1, − 3
= 〈cos(
φ
α
− 3
φ
β
+ 2Ψ
2
)〉. The results are used to estimate the contribution of background effects, associated with local charge conservation coupled to anisotropic flow modulations, to measurements of the CME. A blast-wave parametrisation that incorporates local charge conservation tuned to reproduce the centrality dependent background effects is not able to fully describe the measured
γ
1
,
1
. Finally, the charge and centrality dependence of mixed-harmonics three-particle correlations, of the form
γ
1, 2
= 〈cos(
φ
α
+ 2
φ
β
− 3Ψ
3
)〉, which are insensitive to the CME signal, verify again that background contributions dominate the measurement of
γ
1
,
1
.
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