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.
By exploiting the computing power and local data of distributed clients, federated learning (FL) features ubiquitous properties such as reduction of communication overhead and preserving data ...privacy. In each communication round of FL, the clients update local models based on their own data and upload their local updates via wireless channels. However, latency caused by hundreds to thousands of communication rounds remains a bottleneck in FL. To minimize the training latency, this work provides a multi-armed bandit-based framework for online client scheduling (CS) in FL without knowing wireless channel state information and statistical characteristics of clients. Firstly, we propose a CS algorithm based on the upper confidence bound policy (CS-UCB) for ideal scenarios where local datasets of clients are independent and identically distributed (i.i.d.) and balanced. An upper bound of the expected performance regret of the proposed CS-UCB algorithm is provided, which indicates that the regret grows logarithmically over communication rounds. Then, to address non-ideal scenarios with non-i.i.d. and unbalanced properties of local datasets and varying availability of clients, we further propose a CS algorithm based on the UCB policy and virtual queue technique (CS-UCB-Q). An upper bound is also derived, which shows that the expected performance regret of the proposed CS-UCB-Q algorithm can have a sub-linear growth over communication rounds under certain conditions. Besides, the convergence performance of FL training is also analyzed. Finally, simulation results validate the efficiency of the proposed algorithms.
Objective
The purpose of this study was to investigate whether isolated maternal hypothyroxinaemia (IMH) is associated with risks of small/large‐for‐gestational‐age (SGA/LGA) infants.
Design
...Population‐based prospective cohort study.
Setting
Ma'anshan Maternal and Child Health (MCH) clinics, China.
Population
Pregnant women with singleton births (n = 3178).
Methods
Descriptive statistics were calculated for the demographic characteristics of the mothers and their newborns. Linear regression was applied to estimate the association between thyroid hormone levels and birthweight. Logistic regression was performed to calculate the association between IMH and SGA/LGA.
Main outcome measures
Outcomes included SGA/LGA.
Results
The prevalence of IMH, defined as a free thyroxine value (FT4) lower than the 2.5th percentile with normal thyroid stimulating hormone, was 2.5% (78/3080) and 2.5% (74/2999) in the first and second trimesters, respectively. Additionally, 306 (9.6%) and 524 (16.5%) infants were defined as SGA and LGA, respectively. No evidence supported the notion that IMH is associated with an increased risk for SGA in either the first odds ratio (OR): 1.762, 95% confidence interval (CI): 0.759–4.089 or the second (OR: 0.763, 95% CI: 0.231–2.516) trimester. However, an increased risk of LGA was observed among IMH women in the second trimester (OR: 2.088, 95% CI: 1.193–3.654). Maternal TPO‐Ab positivity in the second trimester increased the risk of SGA (OR: 2.094, 95% CI: 1.333–3.290).
Conclusion
This study provides evidence that IMH is associated with LGA.
Funding
This work was supported by the National Natural Science Foundation of China (No. 81330068).
Tweetable
Isolated maternal hypothyroxinaemia may increase the risk of large‐for‐gestational‐age infants.
Tweetable
Isolated maternal hypothyroxinaemia may increase the risk of large‐for‐gestational‐age infants.
Dielectric loaded graphene plasmon waveguide (DLGPW) is proposed and investigated. An analytical model based on effective-index method is presented and verified by the finite element method ...simulations. The mode effective index, propagation loss, cutoff wavelength of higher order modes and single-mode operation region were derived at mid-infrared spectral region. By changing Fermi energy level, the propagation properties of fundamental mode could be tuned flexibly. The structure of the DLGPW is simple and easy for fabrication. It provided a new freedom to manipulate the graphene surface plasmons, which may led to new applications in actively tunable integrated optical devices.
Abstract
We present an analysis of both Transiting Exoplanet Survey Satellite (TESS) and Zwicky Transient Facility (ZTF) observations of the eclipsing cataclysmic variable IPHAS J051814.34+294113.2 ...(IPHAS J0518). The TESS light curve shows numerous eclipses superimposed on two outbursts, and ZTF data show frequently outbursts recurring on average every 20.7 days and 12.9 days for long and short outbursts, respectively. This makes IPHAS J0518 to be identified as a possible Z Cam-type dwarf nova. Its quiescent magnitude is ∼16.7 in the
g
band. The orbital period is determined to be 4.95 hr. By combining the observed orbital period with the semiempirical relations of Knigge et al., we estimate the donor mass as
M
2
= 0.48
M
⊙
. The eclipse phase measurements are used to constrain the binary parameters. The orbital inclination is limited in the range of 75.°3 ≤
i
< 81.°7, and the mass ratio is derived as 0.33 <
q
≤ 0.73. Furthermore, we analysis the accretion disk eclipse and find that the total disk eclipse is possible during quiescence, whereas during outburst the disk would be only partially obscured. This indicates that the disk will become larger as the outburst proceeds. We also study the changes of the eclipse depth against the out-of-eclipse flux in IPHAS J0518. The results show evidence of the expansion in the disk size and the variations in the radial-temperature gradient during outburst.
BiFeO3 ferrite ceramics were synthesized by spark plasma sintering (SPS) and conventional solid-state synthesis in conjunction with high-energy ball milling. They were evaluated by different ...characterization techniques such as X-ray diffraction, scanning electron microscopy, and dielectric, ferroelectric and magnetic measurements. The 750°C-SPS prepared ceramic samples possessed a single perovskite structure and they were compared with the conventionally synthesized ones. The relative density and average grain size were approximately 95% and <200nm for the SPS-prepared samples, while they were about 89% and >300nm for the conventionally prepared ones. In comparison with the conventionally synthesized ceramics, the SPS-prepared ones exhibited improved dielectric, ferroelectric and magnetic properties. These should be associated with high-density, fine-grained and uniform microstructure created by SPS in conjunction with high-energy ball milling, which could be a promising technique for fabricating high-quality BiFeO3 multiferroic ceramics.
We present a timing analysis of the eclipsing post-common envelope binary (PCEB) DE CVn. Based on new CCD photometric observations and published data, we found that the orbital period in DE CVn has a ...cyclic period oscillation with an amplitude of 28.08 s and a period of 11.22 years plus a rapid period decrease at a rate of . According to the evolutionary theory, secular period decreases in PCEBs arise from angular momentum losses (AMLs) driven by gravitational radiation (GR) and magnetic braking (MB). However, the observed orbital decay is too fast to be produced by AMLs via GR and MB, indicating that there could be another AML mechanism. We suggest that a circumbinary disk around DE CVn may be responsible for the additional AML. The disk mass was derived as a few ×10−4-10−3 M , which is in agreement with that inferred from previous studies in the order of magnitude. The cyclic change is most likely the result of the gravitational perturbation by a circumbinary object due to the Applegate's mechanism failing to explain such a large period oscillation. The mass of the potential third body is calculated as . Supposing the circumbinary companion and the eclipsing binary are coplanar, its mass would correspond to a giant planet. This hypothetical giant planet is moving in a circular orbit of a radius of ∼5.75( 2.02) au around its host star.
Plant flavonoids are generally regarded as natural replacers of synthetic growth promoters in poultry production. This study investigated the immunomodulatory effects of plant flavonoids, such as ...genistein and hesperidin, in lipopolysaccharide (LPS)-challenged broilers. A total of 700 21-day-old commercial Arbor Acres broiler chicks were randomly assigned into six treatment groups, each having six pens of 20 chicks/pen. Chicks were fed a basal diet without any additive (control, CON), 5 mg genistein/kg feed (G5), 20 mg hesperidin/kg (H20), or a basal diet with a combination of genistein and hesperidin (1 : 4) with doses of 5 mg/kg feed (GH5), 10 mg/kg (GH10) and 20 mg/kg (GH20) for 6 weeks. Half of the birds from each treatment were separated, and either challenged with 0·9% sodium chloride solution or Escherichia coli LPS (250 μg/kg BW) on days 16, 18 and 20. The results showed that both genistein and hesperidin improved (P<0.01) the plasma antioxidant status of growing broilers, by increasing total antioxidant capacity (TAOC), superoxide dismutase (SOD) activity and decreasing malondialdehyde production. LPS challenge further increased (P<0.05) TAOC and SOD levels. Regardless of LPS challenge, both genistein and hesperidin improved the humoral and mucosal immunity by increasing the intestinal intraepithelial lymphocyte numbers (P<0.01), as well as anti-Newcastle disease and anti-avian influenza antibody titers (P<0.05). Supplementation of both the plant flavonoids generally increased (P<0.05) the immune organs indices (spleen, thymus and bursa). Thus, supplementation of basal diet of broiler chicks, either with genistein or hesperidin, improved immune and antioxidant status of growing broilers. In addition, combined supplementation of both the flavonoids showed further improvement than individual compounds.
Two pairs of positive-and negative-parity doublet bands together with eight strong electric dipole transitions linking their yrast positive- and negative-parity bands have been identified in ^{78}Br. ...They are interpreted as multiple chiral doublet bands with octupole correlations, which is supported by the microscopic multidimensionally-constrained covariant density functional theory and triaxial particle rotor model calculations. This observation reports the first example of chiral geometry in octupole soft nuclei.
Abstract
We present the discovery and timing results of four pulsars discovered in a pilot survey at intermediate Galactic latitudes with the Five-hundred Aperture Spherical Telescope (FAST). Among ...these pulsars, two belong to the category of millisecond pulsars (MSPs) with spin periods of less than 20 ms. The other two fall under the classification of “mildly recycled” pulsars, with massive white dwarfs as companions. Remarkably, this small survey, covering an area of 4.7 deg
2
, led to the discovery of four recycled pulsars. Such success underscores the immense potential of future surveys at intermediate Galactic latitudes. In order to assess the potential yield of MSPs, we conducted population simulations and found that both FAST and Parkes new phased array feed surveys, focusing on intermediate Galactic latitudes, have the capacity to uncover several hundred new MSPs.
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