ABSTRACT
The dust mass absorption coefficient, κd is the conversion function used to infer physical dust masses from observations of dust emission. However, it is notoriously poorly constrained, and ...it is highly uncertain how it varies, either between or within galaxies. Here we present the results of a proof-of-concept study, using the DustPedia data for two nearby face-on spiral galaxies M 74 (NGC 628) and M 83 (NGC 5236), to create the first ever maps of κd in galaxies. We determine κd using an empirical method that exploits the fact that the dust-to-metals ratio of the interstellar medium is constrained by direct measurements of the depletion of gas-phase metals. We apply this method pixel-by-pixel within M 74 and M 83, to create maps of κd. We also demonstrate a novel method of producing metallicity maps for galaxies with irregularly sampled measurements, using the machine learning technique of Gaussian process regression. We find strong evidence for significant variation in κd. We find values of κd at 500 $\mu$m spanning the range 0.11–0.25 ${\rm m^{2}\, kg^{-1}}$ in M 74, and 0.15–0.80 ${\rm m^{2}\, kg^{-1}}$ in M 83. Surprisingly, we find that κd shows a distinct inverse correlation with the local density of the interstellar medium. This inverse correlation is the opposite of what is predicted by standard dust models. However, we find this relationship to be robust against a large range of changes to our method – only the adoption of unphysical or highly unusual assumptions would be able to suppress it.
A
bstract
The ratio
R
= Γ(
K
S
→ πeν
)
/
Γ(
K
S
→ π
+
π
−
) has been measured with a sample of 300 million
K
S
mesons produced in
ϕ → K
L
K
S
decays recorded by the KLOE experiment at the DAΦNE
e
+
e
...−
collider.
K
S
→ πeν
events are selected by a boosted decision tree built with kinematic variables and time-of-flight measurements. Data control samples of
K
L
→ πeν
decays are used to evaluate signal selection efficiencies. With 49647
±
316 signal events we measure
R
= (1
.
0421
±
0
.
0066
stat
±
0
.
0075
syst
)
×
10
−
3
. The combination with our previous measurement gives
R
= (1
.
0338
±
0
.
0054
stat
±
0
.
0064
syst
)
×
10
−
3
. From this value we derive the branching fraction
B
(
K
S
→ πeν
) = (7
.
153
±
0
.
037
stat
±
0
.
044
syst
)
×
10
−
4
and
f
+
(0)
|V
us
|
= 0
.
2170
±
0
.
009.
Respiratory system is the major route of entry for airborne particulates, being the effect on the human organism dependent on chemical composition of the particles, exposure time and individual ...susceptibility. Airborne particulate trace metals are considered to represent a health hazard since they may be absorbed into human lung tissues during breathing. Fossil fuel and wood combustion, as well as waste incineration and industrial processes, are the main anthropic sources of metals to the atmosphere. In urban areas, vehicular emissions—and dust resuspension associated to road traffic—become the most important manmade source.
This work investigated the atmospheric concentrations of TSP, PM
10 and elements such as iron, manganese, copper and zinc, from three different sites around Salvador Region (Bahia, Brazil), namely: (i)
Lapa Bus Station, strongly impacted by heavy-duty diesel vehicles; (ii)
Aratu harbor, impacted by an intense movement of goods, including metal ores and concentrates and near industrial centers and; (iii)
Bananeira Village located on Maré Island, a non-vehicle-influenced site, with activities such as handcraft work and fishery, although placed near the port. Results have pointed out that TSP concentrations ranged between 16.9 (Bananeira) and 354.0
μg
m
−3 (Aratu#1), while for PM
10 they ranged between 30.9 and 393.0
μg
m
−3, both in the Lapa Bus Station. Iron was the major element in both Lapa Station and Aratu (#1 and #2), with average concentrations in the PM
10 samples of 148.9, 79.6 and 205.0
ng
m
−3, respectively. Zinc, on the other hand, was predominant in samples from Bananeira, with an average concentration of 145.0
ng
m
−3 in TSP samples, since no PM
10 sample was taken from this site. The main sources of iron in the Lapa Station and Aratu harbor were, respectively, soil resuspension by buses and discharge of solid granaries, as fertilizers and metal ores. On the other hand, zinc and copper in the bus station were mainly from anthropic contributions, probably heavy-duty vehicle ageing and wearing actions releasing off Zn from tires and Cu from brake linings. In the Aratu harbor, the high copper concentrations found were probably due to the port's activities, as discharges of copper concentrate on its terminal, although other sources could be possible, as burning of diesel fuel on ships and heavy oil in heaters. Finally, the Bananeira site has been presented as a different profile, since this remote site has shown zinc as the most abundant element, demonstrating to have an unexpected anthropic contribution. On a mass-to-mass basis, both zinc and manganese were in high levels in the Bananeira site and their presence strongly suggest the impact of other sources, such as the Industrial Center of Aratu and/or a siderurgy plant, not far away from that location.
We examined the asymptomatic rates of SARS-CoV-2 infection during the Delta and Omicron waves in the city of São Paulo. Nasopharyngeal swabs were collected at strategic points of the city (open-air ...markets, bus terminals, airports) for SARS-CoV-2 RNA testing. Applying the questionnaire, the symptomatic individuals were excluded, and only asymptomatic cases were analyzed. During the Delta wave, a total of 4315 samples were collected, whereas 2372 samples were collected during the first Omicron wave. The incidence of the asymptomatic SARS-CoV-2 infection was 0.6% during the Delta wave and 0.8% during the Omicron wave. No statistical differences were found in the threshold amplification cycle. However, there was a statistical difference observed in the sublineage distribution between asymptomatic and symptomatic individuals. Our study determined the incidence of asymptomatic infection by monitoring individuals who remained symptom-free, thereby providing a reliable evaluation of asymptomatic SARS-CoV-2 carriage. Our findings reveal a relatively low proportion of asymptomatic cases, which could be attributed to our rigorous monitoring protocol for the presence of clinical symptoms. Investigating asymptomatic infection rates is crucial to develop and implement effective disease control strategies.
Tibio-peroneal trunk (TPT) lesions are usually categorized as ‘complex’ in anatomical classifications, which leads to the perception that endovascular therapy (EVT) will be challenging and the ...outcome most likely poor. This multicenter, retrospective cohort study investigates the efficacy of the EVT of TPT lesions in patients with chronic limb threatening ischemia (CLTI) or an infrapopliteal bypass at risk. The primary endpoint was limb-salvage. The secondary outcomes were technical success, freedom from clinically driven target lesion revascularization (CD-TLR), overall survival, and amputation-free survival. A total of 107 TPT lesions were treated in 101 patients. At 3 years, the limb-salvage rate was 76.4% (95% CI 66.0–86.8%). Technical success was achieved in 96.3% of cases. The freedom from CD-TLR, amputation-free survival, and overall survival at 3 years were 53.0% (95% CI 38.1–67.9%), 33.6% (95% CI 23.0–44.2%), and 47.7% (95% CI 36.1–59.3%), respectively. Reintervention significantly increased the hazard ratio for amputation by 7.65 (95% CI 2.50–23.44, p < 0.001). Our results show that the EVT of both isolated and complex TPT lesions is associated with high technical success and acceptable limb-salvage rates, with reintervention being a major risk factor for amputation. Moreover, mid-term mortality rate was relatively high. In future revisions of the anatomical grading scales, the classification of TPT lesions as highly complex should be reconsidered.
Microbial strains isolated from extreme and understudied environments, such as caves, are still poorly investigated for the production of bioactive secondary metabolites. Investigation of the ethyl ...acetate extract from the growth medium produced by the soil‐derived fungus Aspergillus sp. SDC28, isolated from a Brazilian cave, yielded two anthraquinones: versicolorin C (1) and versiconol (2). The complete assignment of nuclear magnetic resonance and mass spectroscopic data of 1 and 2 was performed for the first time. Moreover, the yet unreported absolute configuration of both compounds was unambiguously established by analysis of experimental and theoretical electronic circular dichroism data. Vibrational circular dichroism was also applied to confirm the absolute stereochemistry of 2. Compounds 1 and 2 showed cytotoxic activity against human ovarian cancer cells (OVCAR3).
Two anthraquinones were isolated from liquid cultures of Aspergillus sp., a soil‐derived fungus from a Brazilian cave. The yet unreported absolute stereochemistry of both compounds was unambiguously established by analysis of experimental and theoretical electronic circular dichroism data. Both compounds presented significant cytotoxic activity on human ovarian cancer cells (OVCAR3).
Neutral kaon pairs produced in ϕ decays in anti-symmetric entangled state can be exploited to search for violation of CPT symmetry and Lorentz invariance. We present an analysis of the CP-violating ...process ϕ→KSKL→π+π−π+π− based on 1.7 fb−1 of data collected by the KLOE experiment at the Frascati ϕ-factory DAΦNE. The data are used to perform a measurement of the CPT-violating parameters Δaμ for neutral kaons in the context of the Standard Model Extension framework. The parameters measured in the reference frame of the fixed stars are:Δa0=(−6.0±7.7stat±3.1syst)×10−18 GeV,ΔaX=(0.9±1.5stat±0.6syst)×10−18 GeV,ΔaY=(−2.0±1.5stat±0.5syst)×10−18 GeV,ΔaZ=(3.1±1.7stat±0.5syst)×10−18 GeV. These are presently the most precise measurements in the quark sector of the Standard Model Extension.
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