We explore the dependence of the incidence of moderate-luminosity (L0.5−8 keV = 1041.9−43.7 erg s-1) active galactic nuclei (AGNs) and the distribution of their accretion rates on host color at 0.5 ...<z < 2.5. Based on the deepest X-ray and UV-to-far-infrared data in the two The Great Observatories Origins Deep Survey (GOODS) fields, we identify 221 AGNs within a mass-complete parent galaxy sample down to M∗ > 1010 M⊙. We use extinction-corrected rest-frame U−V colors to divide both AGN hosts and non-AGN galaxies into red sequence (red), green valley (green), and blue cloud (blue) populations. We find that the fraction of galaxies hosting an AGN at fixed X-ray luminosity increases with stellar mass and redshift for all the three galaxy populations, independent of their colors. However, both the AGN fraction at fixed stellar mass and its evolution with redshift are clearly dependent on host colors. Most notably, red galaxies have the lowest AGN fraction (~5%) at z ~ 1 yet with most rapid evolution with redshift, increasing by a factor of ~5 (24%) at z ~ 2. Green galaxies exhibit the highest AGN fraction across all redshifts, which is most pronounced at z ~ 2 with more than half of them hosting an AGN at M∗ > 1010.6 M⊙. Together with the high AGN fraction in red galaxies at z ~ 2, this indicates that (X-ray) AGNs could be important in both transforming (quenching) star-forming galaxies into quiescent ones and subsequently maintaining their quiescence at high redshift. Furthermore, consistent with previous studies at lower redshifts, we show that the probability of hosting an AGN for the total galaxy population can be characterized by a universal Eddington ratio (as approximated by LX/M∗) distribution (p(λEdd) ~ λEdd-0.4), which is independent on host mass. Yet consistent with their different AGN fractions, galaxies with different colors appear to also have different p(λEdd) with red galaxies exhibiting more rapid redshift evolution compared with that for green and blue galaxies. Evidence for a steeper power-law distribution of p(λEdd) in red galaxies (p(λEdd) ~ λEdd-0.6) is also presented, though larger samples are needed to confirm. These results suggest that the AGN accretion or the growth of supermassive black holes is related to their host properties, and may also influence their hosts in a different mode dependent on the host color.
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FMFMET, NUK, UL, UM, UPUK
Mobile Edge Computing (MEC) is a promising architecture to reduce the energy consumption of mobile devices and provide satisfactory quality-of-service to time-sensitive services. How to jointly ...optimize task offloading and resource allocation to minimize the energy consumption subject to the latency requirement remains an open problem, which motivates this paper. When the latency constraint is taken into account, the optimization variables, including offloading ratio, transmission power, and subcarrier and computing resource allocation, are strongly coupled. To address this issue, we first decompose the original problem into three subproblems named as offloading ratio selection, transmission power optimization, and subcarrier and computing resource allocation. Then, we propose an iterative algorithm to deal with them in a sequence. To be specific, we derive the closed-form solution of offloading ratios, employ the equivalent parametric convex programming to obtain the optimal power allocation policy, and deal with subcarrier and computing resource allocation by the primal-dual method. Simulation results demonstrate that the proposed algorithm can save 20%-40% energy compared with the reference schemes, and can converge to local optimal solutions.
ABSTRACT
We present timing solutions and analyses of 11 pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These pulsars were discovered using an ultrawide ...bandwidth receiver in drift-scan observations made during the commissioning phase of FAST, and were then confirmed and timed using the 64-m Parkes Radio Telescope. Each pulsar has been observed over a span of at least one year. Highlighted discoveries include PSR J0344−0901, which displays mode-changing behaviour and may belong to the class of so-called swooshing pulsars (alongside PSRs B0919+06 and B1859+07); PSR J0803−0942, whose emission is almost completely linearly polarized; and PSRs J1900−0134 and J1945+1211, whose well-defined polarization angle curves place stringent constraints on their emission geometry. We further discuss the detectability of these pulsars by earlier surveys, and highlight lessons learned from our work in carrying out confirmation and monitoring observations of pulsars discovered by a highly sensitive telescope, many of which may be applicable to next-generation pulsar surveys. This paper marks one of the first major releases of FAST-discovered pulsars, and paves the way for future discoveries anticipated from the Commensal Radio Astronomy FAST Survey.
Adaptive routing and efficient packet delivery in Flying Ad Hoc Networks (FANETs) are significant challenges due to underlying environment constraints, such as dynamic nature, mobility, and limited ...connectivity. With the increasing number of machine learning (ML) applications in wireless networks, FANETs can benefit from these data-driven predictions. This letter proposes a Packet Arrival Prediction (PAP) routing protocol to improve transmission link reliability. Primarily, we apply a Long Short-Term Memory (LSTM) model to predict the packet arrival of each UAV, seeking to avoid the high-traffic UAVs, which cause packet loss significantly. Then, we formulate the routing decision issue as an optimization problem, which attempts to find an appropriate path by a proposed constrained sorting approach, in order to make joint yet fast routing decisions. The simulation results demonstrate that the PAP routing protocol outperforms the existing manifold protocols in the aspects of Packet Delivery Ratio (PDR) and delay.
Previously, from the human intestinal flora we isolated the bacterial strain Bacteroides uniformis ZL1, which could convert secoisolariciresinol diglucoside (SDG) to its aglycone secoisolariciresinol ...(SECO) in vivo. In this study, 24 putative β-glucosidase genes were screened from the genome of B. uniformis ATCC 8492, which were used as templates to design PCR primers for the target genes in B. uniformis ZL1. Fifteen genes (bgl1–bgl15) were amplified from strain ZL1, and among them we identified bgl8 as the gene encoding the SDG-hydrolyzing β-glucosidase. We sequenced the bgl8 gene, cloned it into the expression vector and then transformed Escherichia coli to construct the recombinant bacteria that could synthesize the target β-glucosidase (BuBGL8). We purified and characterized BuBGL8, which showed maximal activity and stability under the culture conditions of pH 6.0 and 30 °C. SDG (2.0 mg/ml) was converted to SECO by both the purified BuBGL8 (0.035 mg/ml) and crude enzyme extract (0.23 mg crude protein/ml) with the efficiency of more than 90 % after 90 min at the reaction conditions. This is, to our knowledge, the first report of using recombinant bacteria to synthesize the SDG-hydrolyzing β-glucosidase, which could be used to produce SECO from SDG conveniently and highly efficiently.
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CEKLJ, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract Background and objectives The aim of the study was to investigate the correlation between AKR1B10 expression and clinicopathological features of gastric cancer (GC). Methods Real-time ...polymerase chain reaction (RT-PCR) was performed to determine AKR1B10 mRNA expression. AKR1B10 protein levels were measured by immunohistochemistry. Results RT-PCR analysis confirmed that AKR1B10 was significantly down-regulated in gastric cancer compared with paired, normal mucosa. Immunohistochemistry revealed that the percentage of AKR1B10-positive specimens was lower in gastric carcinoma compared with normal specimens. The frequency of AKR1B10-positive GC specimens was higher in patients with tumor size <5 cm, no lymph node metastasis, no distant metastasis and lower tumor stages The mean survival time for patients in the AKR1B10-positive group was significantly higher compared with the AKR1B1-negative group. The 5-year survival rate for the AKR1B10-positive group was also significantly higher than for the AKR1B1-negative group. Cox regression analysis revealed that AKR1B10 expression is an independent prognostic factor of GC. Conclusions Expression of AKR1B10 in gastric cancer was significantly associated with tumor size, lymph node metastasis, distance metastasis and TNM stage, and AKR1B10 may be a good prognostic indicator in gastric cancer.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
The metal-insulator transition temperature
T
c
in VO
2
is experimentally shown to be almost the same as a magnetic transition temperature
T
m
characterized by an abrupt decrease in ...susceptibility, suggesting the evidence of the same underlying origin for both transitions. The measurement of susceptibility shows that it weakly increases on cooling for temperature range of
T
>
T
m
, sharply decreases near
T
m
and then unusually increases on further cooling. A theoretical approach for such unusual observations in susceptibility near
T
m
or below is performed by modeling electrons from each two adjacent V
4+
ions distributed along V-chains as a two-electron system, which indicates that the spin exchange between electrons could cause a level splitting into a singlet (
S
= 0) level of lower energy and a triplet (
S
= 1) level of higher energy. The observed abrupt decrease in susceptibility near
T
m
is explained to be due to that the sample enters the singlet state in which two electrons from adjacent V
4+
ions are paired into dimers in spin antiparallel. By considering paramagnetic contribution of unpaired electrons created by the thermal activation from singlet to triplet levels, an expression for susceptibility is proposed to quantitatively explain the unusual temperature-dependent susceptibility observed at low temperatures. Based on the approach to magnetic features, the observed metal-insulator transition is explained to be due to a transition from high-temperature Pauli paramagnetic metallic state of V
4+
ions to low-temperature dimerized state of strong electronic localization.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
With the increasing rate of overweight and obesity in children worldwide, adiposity rebound(AR)closely related to obesity has become the spotlight, and early AR phase has a broad impact on pubertal ...development in girls, but the specific mechanism of action isn't very clear.This paper is review of the prevalence of early AR at home and abroad, and its influencing factors, the impact of AR on the adolescent development of girls and related mechanisms, to identify high-risk individuals with early AR, early AR to identify early adolescent development, and take early intervention measures to promote children's health.
In 5G heterogeneous networking, it is promising to integrate different wireless networks to provide higher data rate. This paper models the integrated system as a receiver frequency division relay ...channel (RFDRC) and studies how to improve the transmission rate by combining decode-forward (DF), compress-forward (CF), and amplify-forward (AF) schemes. First, we establish clear criterions on how to select a relay scheme among DF, CF, and AF schemes and prove that the CF outperforms AF for all possible configurations. Based on the scheme selection criterions, we propose a hybrid DF-CF scheme which takes advantage of both DF and CF schemes in RFDRC. A near-optimal resource allocation is presented for the DF-CF-based system, leading to a new achievable rate for RFDRC. For ease of implementation, we further put forward a hybrid DF-AF scheme and reconsider the joint bandwidth and power allocation. Two suboptimal resource allocation solutions are established. In particular, when source frequency band and relay frequency band have equivalent bandwidth, we show that the proposed hybrid DF-AF scheme can achieve the concave envelope of the maximum between DF rate and AF rate. Numerical results show that the proposed schemes bring significant gains for RFDRC.
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