We present a search for a neutrino signal from dark matter self-annihilations in the Milky Way using the IceCube Neutrino Observatory (IceCube). In 1005 days of data we found no significant excess of ...neutrinos over the background of neutrinos produced in atmospheric air showers from cosmic ray interactions. We derive upper limits on the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles
⟨
σ
A
v
⟩
. Upper limits are set for dark matter particle candidate masses ranging from 10 GeV up to 1 TeV while considering annihilation through multiple channels. This work sets the most stringent limit on a neutrino signal from dark matter with mass between 10 and 100 GeV, with a limit of
1.18
·
10
-
23
cm
3
s
-
1
for 100 GeV dark matter particles self-annihilating via
τ
+
τ
-
to neutrinos (assuming the Navarro–Frenk–White dark matter halo profile).
Secondary organic aerosol (SOA) formation from ambient air was studied using
an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer
(AMS) during both the wet and dry seasons at the ...Observations and Modeling
of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were
made at two sites downwind of the city of Manaus, Brazil. Ambient air was
oxidized in the OFR using variable concentrations of either OH or O3,
over ranges from hours to days (O3) or weeks (OH) of equivalent
atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as
much as 10 µg m−3, depending on the amount of SOA precursor
gases in ambient air. Typically, more SOA was formed during nighttime than
daytime, and more from OH than from O3 oxidation. SOA yields of
individual organic precursors under OFR conditions were measured by standard
addition into ambient air and were confirmed to be consistent with published
environmental chamber-derived SOA yields. Positive matrix factorization of
organic aerosol (OA) after OH oxidation showed formation of typical oxidized
OA factors and a loss of primary OA factors as OH aging increased. After OH
oxidation in the OFR, the hygroscopicity of the OA increased with increasing
elemental O:C up to O:C∼1.0, and then decreased as O:C
increased further. Possible reasons for this decrease are discussed. The
measured SOA formation was compared to the amount predicted from the
concentrations of measured ambient SOA precursors and their SOA yields.
While measured ambient precursors were sufficient to explain the amount of
SOA formed from O3, they could only explain 10–50 % of the SOA
formed from OH. This is consistent with previous OFR studies, which showed
that typically unmeasured semivolatile and intermediate volatility gases
(that tend to lack C=C bonds) are present in ambient air and can explain
such additional SOA formation. To investigate the sources of the unmeasured
SOA-forming gases during this campaign, multilinear regression analysis was
performed between measured SOA formation and the concentration of gas-phase
tracers representing different precursor sources. The majority of
SOA-forming gases present during both seasons were of biogenic origin. Urban
sources also contributed substantially in both seasons, while biomass
burning sources were more important during the dry season. This study
enables a better understanding of SOA formation in environments with diverse
emission sources.
Magnaporthe grisea is the most destructive pathogen of rice worldwide and the principal model organism for elucidating the molecular basis of fungal disease of plants. Here, we report the draft ...sequence of the M. grisea genome. Analysis of the gene set provides an insight into the adaptations required by a fungus to cause disease. The genome encodes a large and diverse set of secreted proteins, including those defined by unusual carbohydrate-binding domains. This fungus also possesses an expanded family of G-protein-coupled receptors, several new virulence-associated genes and large suites of enzymes involved in secondary metabolism. Consistent with a role in fungal pathogenesis, the expression of several of these genes is upregulated during the early stages of infection-related development. The M. grisea genome has been subject to invasion and proliferation of active transposable elements, reflecting the clonal nature of this fungus imposed by widespread rice cultivation.
Isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA) can contribute substantially to organic aerosol (OA) concentrations in forested areas under low NO conditions, hence significantly ...influencing the regional and global OA budgets, accounting, for example, for 16–36 % of the submicron OA in the southeastern United States (SE US) summer. Particle evaporation measurements from a thermodenuder show that the volatility of ambient IEPOX-SOA is lower than that of bulk OA and also much lower than that of known monomer IEPOX-SOA tracer species, indicating that IEPOX-SOA likely exists mostly as oligomers in the aerosol phase. The OH aging process of ambient IEPOX-SOA was investigated with an oxidation flow reactor (OFR). New IEPOX-SOA formation in the reactor was negligible, as the OFR does not accelerate processes such as aerosol uptake and reactions that do not scale with OH. Simulation results indicate that adding ∼ 100 µg m−3 of pure H2SO4 to the ambient air allows IEPOX-SOA to be efficiently formed in the reactor. The heterogeneous reaction rate coefficient of ambient IEPOX-SOA with OH radical (kOH) was estimated as 4.0 ± 2.0 × 10−13 cm3 molec−1 s−1, which is equivalent to more than a 2-week lifetime. A similar kOH was found for measurements of OH oxidation of ambient Amazon forest air in an OFR. At higher OH exposures in the reactor (> 1 × 1012 molec cm−3 s), the mass loss of IEPOX-SOA due to heterogeneous reaction was mainly due to revolatilization of fragmented reaction products. We report, for the first time, OH reactive uptake coefficients (γOH = 0.59 ± 0.33 in SE US and γOH = 0.68 ± 0.38 in Amazon) for SOA under ambient conditions. A relative humidity dependence of kOH and γOH was observed, consistent with surface-area-limited OH uptake. No decrease of kOH was observed as OH concentrations increased. These observations of physicochemical properties of IEPOX-SOA can help to constrain OA impact on air quality and climate.
A
bstract
Using
e
+
e
−
collision data collected at the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, corresponding to an integrated luminosity of 7
.
33 fb
−
1
, we ...determine the absolute branching fractions of fifteen hadronic
D
s
+
decays with a double-tag technique. In particular, we make precise measurements of the branching fractions
B
D
s
+
→
K
+
K
−
π
+
=
5.49
±
0.04
±
0.07
%
,
B
D
s
+
→
K
S
0
K
+
=
1.50
±
0.01
±
0.01
%
and
B
D
s
+
→
K
+
K
−
π
+
π
0
=
5.50
±
0.05
±
0.11
%
, where the first uncertainties are statistical and the second ones are systematic. The
CP
asymmetries in these decays are also measured and all are found to be compatible with zero.
Although winter dysentery (WD), which is caused by the bovine coronavirus (BCoV) is characterized by the sudden onset of diarrhea in many adult cattle in a herd, the pathogenesis of the WD-BCoV is ...not completely understood. In this study, colostrum-deprived calves were experimentally infected with a Korean WD-BCoV strain and examined for viremia, enteric and nasal virus shedding as well as for viral antigen expression and virus-associated lesions in the small and large intestines and the upper and lower respiratory tract from 1 to 8 days after an oral infection. The WD-BCoV-inoculated calves showed gradual villous atrophy in the small intestine and a gradual increase in the crypt depth of the large intestine. The WD-BCoV-infected animals showed epithelial damage in nasal turbinates, trachea and lungs, and interstitial pneumonia. The WD-BCoV antigen was detected in the epithelium of the small and large intestines, nasal turbinates, trachea and lungs. WD-BCoV RNA was detected in the serum from post-inoculation day 3. These results show that the WD-BCoV has dual tropism and induces pathological changes in both the digestive and respiratory tracts of calves. To our knowledge, this is the first detailed report of dual enteric and respiratory tropisms of WD-BCoV in calves. Comprehensive studies of the dual tissue pathogenesis of the BCoV might contribute to an increased understanding of similar pneumoenteric CoV infections in humans.
Aim: To study the associations between fish intake and academic achievement as cognitive parameter among Swedish adolescents.
Methods: In 2000, a questionnaire including respiratory items, ...socioeconomic conditions and dietary information was mailed to all schoolchildren (n = 18 158), aged 15 and living in Västra Götaland region of Sweden. The questionnaire was returned by 10 837 subjects. One year later, the total school grades for each subject who had completed the questionnaire and who included their full personal identification number were obtained from the national registers. Multiple linear regression models were applied to evaluate the association between fish intake and academic grades among 9448 schoolchildren, while adjusting for potential confounders, e.g. parents’ education.
Results: Grades were higher in subjects with fish consumption once a week compared with subjects with fish consumption of less than once a week (reference group) increment in estimate 14.5, 95% confidence interval (CI) 11.8–17.1. Grades were even higher in subjects with fish consumption of more than once a week compared with the reference group (increment in estimate 19.9, 95% CI 16.5–23.3). In the model stratified for parents’ education, there were still higher grades among subjects with frequent fish intake in all educational strata (p < 0.01).
Conclusion: Frequent fish intake among schoolchildren may provide benefits in terms of academic achievement.
Studies of the decay Ds+→K+K−μ+νμ Bakina, O.; Balossino, I.; Ban, Y. ...
The journal of high energy physics,
12/12, Letnik:
2023, Številka:
12
Journal Article
Recenzirano
Odprti dostop
A
bstract
The
D
s
+
→
K
+
K
−
μ
+
ν
μ
decay is studied based on 7.33 fb
−
1
of
e
+
e
−
collision data collected with the BESIII detector at center-of-mass energies in the range from 4.128 to 4.226 ...GeV. The absolute branching fraction is measured as
B
D
s
+
→
ϕ
μ
+
ν
μ
=
2.25
±
0.09
±
0.07
×
10
−
2
, the most precise measurement to date. Combining with the world average of
B
D
s
+
→
ϕ
e
+
ν
e
, the ratio of the branching fractions obtained is
B
D
s
+
→
ϕ
μ
+
ν
μ
B
D
s
+
→
ϕ
e
+
ν
e
=
0.94
±
0.08
, in agreement with lepton universality. By performing a partial wave analysis, the hadronic form factor ratios at
q
2
= 0 are extracted, finding
r
V
=
V
0
A
1
0
=
1.58
±
0.17
±
0.02
and
r
2
=
A
2
0
A
1
0
=
0.71
±
0.14
±
0.02
, where the first uncertainties are statistical and the second are systematic. No significant
S
-wave contribution from
f
0
(980)
→ K
+
K
−
is found. The upper limit
B
D
s
+
→
f
0
980
μ
+
ν
μ
⋅
B
f
0
980
→
K
+
K
−
<
5.45
×
10
−
4
is set at 90% credibility level.
A
bstract
Using 15
.
6 fb
−
1
of
e
+
e
−
collision data collected at twenty-four center-of-mass energies from 4
.
0 to 4
.
6 GeV with the BESIII detector, the helicity amplitudes of the process
e
+
e
...−
→
π
+
π
−
ω
are analyzed for the first time. Born cross section measurements of two-body intermediate resonance states with statistical significance greater than 5
σ
are presented, such as
f
0
(500),
f
0
(980),
f
2
(1270),
f
0
(1370),
b
1
(1235)
±
, and
ρ
(1450)
±
. In addition, evidence of a resonance state in
e
+
e
−
→
π
+
π
−
ω
production is found. The mass of this state obtained by line shape fitting is about 4
.
2 GeV/
c
2
, which is consistent with the production of
ψ
(4160) or
Y
(4220).
A
bstract
Using
e
+
e
−
collision datasets corresponding to a total integrated luminosity of 21.7 fb
−
1
collected with the BESIII detector at the BEPCII collider at center-of-mass energies ranging ...from 4.009 GeV to 4.951 GeV, the energy-dependent cross sections of
e
+
e
−
→
p
K
−
Λ
¯
+
c
.
c
.
are measured for the first time. By fitting these energy-dependent cross sections, we search for the excited
ψ
states
ψ
(4160) and
ψ
(4415), and the vector charmonium-like states
ψ
(4230),
ψ
(4360), and
ψ
(4660). No evidence for these is observed and the upper limits on the branching fractions of these states decaying into
p
K
−
Λ
¯
+
c
.
c
.
are set at the 90% confidence level.
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