Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the ...search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28} cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25} cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.
The aim of this meta-analysis was to evaluate the efficacy of Tai chi (TC) as an adjuvant treatment for osteopenia and primary osteoporosis.
We went through eight databases to identify relevant ...randomized controlled trials that compared TC with a control group. The primary outcome was osteoporosis-related fractures (fracture incidence). Meta-analyses and trial sequential analyses (TSA) were conducted using RevMan 5.3 and TSA 0.9.
Fifteen randomized controlled trials involving a total of 857 patients were included in the analyses. No trials reported primary outcome; however, bone mineral density (BMD) values differed significantly in subgroup 1 (TC vs no treatment; weighted mean difference WMD =0.05 g/cm
, 95% CI 0.03 to 0.07;
<0.00001;
for heterogeneity =0.22,
=22%) and subgroup 2 (TC vs conventional treatments; WMD =0.16 g/cm
, 95% CI 0.11 to 0.21;
<0.00001;
for heterogeneity =0.008,
=75%). In addition, two trials compared TC with conventional treatments, which found a significant difference in bone gla protein (standardized mean difference =-1.18, 95% CI -1.66 to -0.70;
<0.00001;
for heterogeneity =0.58,
=75%). The results of the BMD were confirmed by TSA. Also, TC may have a certain effect on the relief of osteoporotic pain (WMD = -2.61, 95% CI -3.51 to -1.71; WMD = -1.39, 95% CI -2.01 to -0.77). However, it did not promote the quality of life, level of serum calcium, serum phosphorus, and also had no effect on bone turnover markers.
Although there is no study monitoring fracture incidence, TC may be beneficial for patients in improving BMD values, level of bone gla protein, and relieving osteoporotic pain. However, due to the low methodological quality, current evidence for treating osteopenia and primary osteoporosis through TC is insufficient.
Carbapenem-resistant
(CRKP) infections have been increasingly reported worldwide. We aimed to identify the risk factors for nosocomial CRKP infections and assess the clinical outcomes.
We conducted a ...case-control study with data collected from January 2016 to December 2018 in China. Controls were selected at a ratio of 1:1 from patients with nosocomial carbapenem-susceptible
(CSKP) infections. Risk factors for nosocomial CRKP infections and clinical outcomes were assessed with univariate and multivariate analyses.
A total of one hundred forty-two patients with CRKP infections and one hundred forty-two patients with CSKP infections were enrolled in this study. Multivariate analysis showed that exposure to antibiotics within 3 months prior to admission (odds ratio OR, 2.585; 95% confidence interval CI, 1.425-4.691; P=0.002), exposure to carbapenems (OR, 2.532; 95% CI, 1.376-4.660; P=0.003), exposure to fluoroquinolones (OR, 3.309; 95% CI, 1.326-8.257; P=0.010), and the presence of a nasogastric tube (OR, 2.796; 95% CI, 1.369-5.712; P=0.005) were independent risk factors for CRKP infections. The 30-day mortality rate in the CRKP group was 19.7%, while the in-hospital mortality rate was 28.9%. In the CRKP group, a higher creatinine level (OR, 1.009; 95% CI, 1.002-1.016; P = 0.013), being in shock at the time of a positive culture (OR, 4.454; 95% CI, 1.374-14.443; P = 0.013), and co-infection with other resistant bacteria (OR, 4.799; 95% CI, 1.229-18.740; P = 0.024) were independent predictors of in-hospital mortality in patients with CRKP infections. Kaplan-Meier curves showed that the CRKP group had a shorter survival time than the CSKP group.
Nosocomial CRKP infection was associated with exposure to carbapenems and fluoroquinolones within 3 months prior to hospitalization and the presence of a nasogastric tube. Patients infected with CRKP had higher 30-day and in-hospital mortality rates. A higher creatinine level, shock and co-infection with other resistant bacteria were independent predictors of in-hospital mortality in patients with CRKP infections.
The increasing number of vehicles in cities brings new challenges to urban traffic management. Analyzing and modeling traffic is of great practical significance to urban intelligent traffic ...management. In this paper, the existing traffic simulation research is reviewed and summarized. Firstly, the crowd modeling and crowd animation are analyzed by referring to the idea of crowd simulation. Secondly, it compares and analyzes various existing car following technologies, and points out that animated traffic simulation is a hotspot in traffic simulation research. And then the concept of affective computing is integrated into the traffic simulation, considering the impacts of drivers’ emotion on vehicle driving and it is pointed out that the emotion-driven traffic flow is more authentic. Finally, combined with the status quo, the existing research drawbacks are analyzed, and the direction of future traffic simulation is pointed out.
The temperature and dc bias stability of the dielectric constant and loss tangent of CaCu3Ti4O12 samples sintered under different oxygen atmospheres are discussed. The results suggest that the ...metal-oxygen vacancy related defects not only provide the charge carriers for the conduction (defect doping) but also contribute to the huge permittivity in the way of defect dipoles repositioning under charge carrier hopping. The charge localization in a specific copper-oxygen vacancy defect complex is the reason of the huge and stable permittivity and low dielectric loss in the middle temperature range, 90 K-200 K (20 Hz), while the implementation of the large barrier layer height needs a contribution by the titanium oxygen vacancy related trap charges in the grain boundaries, which also lead to a second permittivity stable range in a higher temperature range 200 K–300 K.
Aims.
In the presence of a sufficient amount of target material,
γ
-rays can be used as a tracer in the search for sources of Galactic cosmic rays (CRs). Here we present deep observations of the ...Galactic center (GC) region with the MAGIC telescopes and use them to infer the underlying CR distribution and to study the alleged PeV proton accelerator at the center of our Galaxy.
Methods.
We used data from ≈100 h observations of the GC region conducted with the MAGIC telescopes over five years (from 2012 to 2017). Those were collected at high zenith angles (58−70 deg), leading to a larger energy threshold, but also an increased effective collection area compared to low zenith observations. Using recently developed software tools, we derived the instrument response and background models required for extracting the diffuse emission in the region. We used existing measurements of the gas distribution in the GC region to derive the underlying distribution of CRs. We present a discussion of the associated biases and limitations of such an approach.
Results.
We obtain a significant detection for all four model components used to fit our data (Sgr A*, “Arc”, G0.9+0.1, and an extended component for the Galactic Ridge). We observe no significant difference between the
γ
-ray spectra of the immediate GC surroundings, which we model as a point source (Sgr A*) and the Galactic Ridge. The latter can be described as a power-law with index 2 and an exponential cut-off at around 20 TeV with the significance of the cut-off being only 2
σ
. The derived cosmic-ray profile hints to a peak at the GC position and with a measured profile index of 1.2 ± 0.3 is consistent with the 1/
r
radial distance scaling law, which supports the hypothesis of a CR accelerator at the GC. We argue that the measurements of this profile are presently limited by our knowledge of the gas distribution in the GC vicinity.
A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal ...strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous DMSO, a total of 181 mutants were obtained by single colony isolation. In contrast to the strain G59, the EtOAc extracts of nine mutant cultures showed inhibitory effects on K562 cells, indicating that the nine mutants had acquired capability to produce antitumor metabolites. This was evidenced by TLC and HPLC analysis of EtOAc extracts of G59 and the nine mutants. Further isolation and characterization demonstrated that four antitumor secondary metabolites, janthinone (1), fructigenine A (2), aspterric acid methyl ester (3) and citrinin (4), were newly produced by mutant 5-1-4 compared to the parent strain G59, and which were also not found in the secondary metabolites of other Penicillium purpurogenum strains. However, Compounds 1-4 inhibited the proliferation of K562 cells with inhibition rates of 34.6% (1), 60.8% (2), 31.7% (3) and 67.1% (4) at 100 μg/mL, respectively. The present study demonstrated the effectiveness of a simple, yet practical approach to activate the production of dormant fungal secondary metabolites by introducing acquired resistance to aminoglycoside antibiotics, which could be applied to the studies for eliciting dormant metabolic potential of fungi to obtain cryptic secondary metabolites.
We report the detection of pulsed gamma-ray emission from the Geminga pulsar (PSR J0633+1746) between 15 GeV and 75 GeV. This is the first time a middle-aged pulsar has been detected up to these ...energies. Observations were carried out with the MAGIC telescopes between 2017 and 2019 using the low-energy threshold Sum-Trigger-II system. After quality selection cuts, ∼80 h of observational data were used for this analysis. To compare with the emission at lower energies below the sensitivity range of MAGIC, 11 years of
Fermi
-LAT data above 100 MeV were also analysed. From the two pulses per rotation seen by
Fermi
-LAT, only the second one,
P
2, is detected in the MAGIC energy range, with a significance of 6.3
σ
. The spectrum measured by MAGIC is well-represented by a simple power law of spectral index Γ = 5.62 ± 0.54, which smoothly extends the
Fermi
-LAT spectrum. A joint fit to MAGIC and
Fermi
-LAT data rules out the existence of a sub-exponential cut-off in the combined energy range at the 3.6
σ
significance level. The power-law tail emission detected by MAGIC is interpreted as the transition from curvature radiation to Inverse Compton Scattering of particles accelerated in the northern outer gap.
Abstract
Introduction
Sleep deprivation (SD) significantly impairs vigilance attention and reduces the ability to maintain a consistent alertness level. The Psychomotor Vigilance Test (PVT) is a ...widely used and highly sensitive vigilance task for sleep studies, which records reaction times (RT) to visual stimuli that occurs at random inter-stimulus intervals (ISI). Previous studies have shown that longer ISI facilitates faster RT on the PVT. Although the negative effects of sleep loss on PVT performance have been well documented, whether and how SD modulates the ISI effect on vigilant attention remain elusive. Here we studied this question using a large PVT data set.
Methods
Seventy health adults (33.9 ± 8.8y, 41 males) participated in a 5-day and 4-night in-laboratory controlled sleep study, including n=54 in the experimental group involving 36-hour of acute total SD (TSD) followed by two nights of recovery sleep, and n=16 in the control group without SD. All participants completed a cognitive test battery every 2 hours while awake, including a 10-min standard PVT and a 3-min brief PVT (PVT-B). A total of 1766 PVT and 1622 PVT-B tests data were included. The linear approach to threshold with ergodic rate (LATER) model was used to fit the data.
Results
Reliable effects of ISI on vigilant attention were found for the PVT and PVT-B in both experimental and control groups, such that RT decreased monotonically with longer ISI. The LATER model indicated that changes in perceptual sensitivity rather than threshold adjustment may underlie this ISI effect. A larger ISI effect was found for PVT tests after TSD compared to those after baseline or recovery sleep (p<0.001), whereas no differences were found between PVT tests after baseline or recovery sleep in the SD group, nor among PVT tests on different days in the control group.
Conclusion
Our results suggest that sleep deprivation increases the ISI effect on both standard 10-min and brief 3-min PVT, which may be due to altered perceptual sensitivity of time intervals after sleep loss.
Support (If Any)
Supported in part by NIH grants R01-HL102119, R01-MH107571, R01-NR004281, and CTRC UL1RR024134.
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