89 research outputs found
Managerial ability, financial performance and goodwill impairment: A moderated mediation analysis
This paper examines whether and how managerial ability affects the likelihood of goodwill impairment of Chinese publicly listed companies over the period 2007-2017. We document a negative relationship between goodwill impairment and managerial ability, and uncover the mediation effect of corporate financial performance. Moreover, we find that the mediation effect is moderated by firms’ earnings smoothing motivation and state ownership. The results suggest that when a company has the motivation to smooth earnings or is owned by the government, higher managerial ability of the company does not necessarily reduce the likelihood of goodwill impairment. The findings have important implications for investors and regulators
Does managerial ability affect corporate financial constraints? Evidence from China
We study the effect of managerial ability on financial constraints
of Chinese listed companies. Our results indicate a negative relationship between managerial ability and corporate financial constraints. Further analyses show that managerial ability helps
alleviate financial constraints probably through lowering information asymmetry, reducing agency conflicts and enhancing corporate profitability. In addition, we find evidence that private firms
suffer from more severe financial constraints than state- and foreign-owned firms, and the effect of managerial ability in alleviating financial constraints is more pronounced for private firms.
Overall, our findings help understand the role and highlight the
importance of managerial ability in alleviating financial
constraints
RefineDetLite: A Lightweight One-stage Object Detection Framework for CPU-only Devices
Previous state-of-the-art real-time object detectors have been reported on
GPUs which are extremely expensive for processing massive data and in
resource-restricted scenarios. Therefore, high efficiency object detectors on
CPU-only devices are urgently-needed in industry. The floating-point operations
(FLOPs) of networks are not strictly proportional to the running speed on CPU
devices, which inspires the design of an exactly "fast" and "accurate" object
detector. After investigating the concern gaps between classification networks
and detection backbones, and following the design principles of efficient
networks, we propose a lightweight residual-like backbone with large receptive
fields and wide dimensions for low-level features, which are crucial for
detection tasks. Correspondingly, we also design a light-head detection part to
match the backbone capability. Furthermore, by analyzing the drawbacks of
current one-stage detector training strategies, we also propose three
orthogonal training strategies---IOU-guided loss, classes-aware weighting
method and balanced multi-task training approach. Without bells and whistles,
our proposed RefineDetLite achieves 26.8 mAP on the MSCOCO benchmark at a speed
of 130 ms/pic on a single-thread CPU. The detection accuracy can be further
increased to 29.6 mAP by integrating all the proposed training strategies,
without apparent speed drop.Comment: 16 pages, 8 figure
PGC 38025: A Star-forming Lenticular Galaxy With an Off-nuclear Star-forming Core
Lenticular galaxies (S0s) were considered mainly as passive evolved spirals
due to environmental effects for a long time; however, most S0s in the field
cannot fit into this common scenario. In this work, we study one special case,
SDSS J120237.07+642235.3 (PGC 38025), a star-forming field S0 galaxy with an
off-nuclear blue core. We present optical integral field spectroscopic (IFS)
observation with the 3.5 meter telescope at Calar Alto (CAHA) Observatory, and
high-resolution millimeter observation with the NOrthern Extended Millimeter
Array (NOEMA). We estimated the star formation rate (SFR = 0.446 ) and gaseous metallicity (12 + log(O/H) = 8.42) for PGC 38025, which
follows the star formation main sequence and stellar mass - metallicity
relation. We found that the ionized gas and cold molecular gas in PGC 38025
show the same spatial distribution and kinematics, whilst rotating misaligned
with stellar component. The off-nuclear blue core is locating at the same
redshift as PGC 38025 and its optical spectrum suggest it is \rm H\,{\sc ii}
region. We suggest that the star formation in PGC 38025 is triggered by a
gas-rich minor merger, and the off-nuclear blue core might be a local
star-formation happened during the accretion/merger process.Comment: 16 pages, 13 figures, accepted for publication in Ap
Characteristics and outcomes of heart failure with recovered left ventricular ejection fraction
Aims
There is an emerging interest in elucidating the natural history and prognosis for patients with heart failure with reduced ejection fraction (HFrEF) in whom left ventricular ejection fraction (LVEF) subsequently improves. The characteristics and outcomes were compared between heart failure with recovered ejection fraction (HFrecEF) and persistent HFrEF.
Methods and results
This is a retrospective study of adults who underwent at least two echocardiograms 3 months apart between 1 November 2015 and 31 October 2019 with an initial diagnosis of HFrEF. The subjects were divided into HFrecEF group (second LVEF > 40%, ≥10% absolute improvement in LVEF) and persistent HFrEF group (20% subgroups. The primary outcomes were all-cause mortality and rehospitalization. A total of 1160 HFrEF patients were included [70.2% male, mean (standard deviation) age: 62 ± 13 years]. On the second echocardiogram, 284 patients (24.5%) showed HFrecEF and 876 patients (75.5%) showed persistent HFrEF. All-cause mortality was identified in 23 (8.10%) HFrecEF and 165 (18.84%) persistent HFrEF, whilst 76 (26.76%) and 426 (48.63%) showed rehospitalizations, respectively. Survival analysis showed that the persistent HFrEF subgroup experienced a significantly higher mortality at 12 and 24 months and a higher hospitalization at 12, 24, 48, and more than 48 months following discharge. Multivariate Cox regression showed that persistent HFrEF had a higher risk of all-cause mortality [hazard ratio (HR) 2.30, 95% confidence interval (CI) 1.49–3.56, P = 0.000] and rehospitalization (HR 1.85, 95% CI 1.45–2.36, P = 0.000) than the HFrecEF group. Subgroup analysis showed that the LVEF ≥ 20% improvement subgroup had lower rates of adverse outcomes compared with those with less improvement of 10–20%.
Conclusions
Heart failure with recovered ejection fraction is a distinct HF phenotype with better clinical outcomes compared with those with persistent HFrEF. HFrecEF patients have a relatively better short-term mortality at 24 months but not thereafter
Comparative expression profiles of carboxylesterase orthologous CXE14 in two closely related tea geometrid species, Ectropis obliqua Prout and Ectropis grisescens Warren
Insect carboxylesterases (CXEs) can be expressed in multiple tissues and play crucial roles in detoxifying xenobiotic insecticides and degrading olfactory cues. Therefore, they have been considered as an important target for development of eco-friendly insect pest management strategies. Despite extensive investigation in most insect species, limited information on CXEs in sibling moth species is currently available. The Ectropis obliqua Prout and Ectropis grisescens Warren are two closely related tea geometrid species, which share the same host of tea plant but differ in geographical distribution, sex pheromone composition, and symbiotic bacteria abundance, providing an excellent mode species for studies of functional diversity of orthologous CXEs. In this study, we focused on EoblCXE14 due to its previously reported non-chemosensory organs-biased expression. First, the EoblCXE14 orthologous gene EgriCXE14 was cloned and sequence characteristics analysis showed that they share a conserved motif and phylogenetic relationship. Quantitative real-time polymerase chain reaction (qRT-PCR) was then used to compare the expression profiles between two Ectropis spp. The results showed that EoblCXE14 was predominately expressed in E. obliqua larvae, whereas EgriCXE14 was abundant in E. grisescens at multiple developmental stages. Interestingly, both orthologous CXEs were highly expressed in larval midgut, but the expression level of EoblCXE14 in E. obliqua midgut was significantly higher than that of EgriCXE14 in E. grisescens midgut. In addition, the potential effect of symbiotic bacteria Wolbachia on the CXE14 was examined. This study is the first to provide comparative expression profiles of orthologous CXE genes in two sibling geometrid moth species and the results will help further elucidate CXEs functions and identify a potential target for tea geometrid pest control
Jump-Start Reinforcement Learning
Reinforcement learning (RL) provides a theoretical framework for continuously
improving an agent's behavior via trial and error. However, efficiently
learning policies from scratch can be very difficult, particularly for tasks
with exploration challenges. In such settings, it might be desirable to
initialize RL with an existing policy, offline data, or demonstrations.
However, naively performing such initialization in RL often works poorly,
especially for value-based methods. In this paper, we present a meta algorithm
that can use offline data, demonstrations, or a pre-existing policy to
initialize an RL policy, and is compatible with any RL approach. In particular,
we propose Jump-Start Reinforcement Learning (JSRL), an algorithm that employs
two policies to solve tasks: a guide-policy, and an exploration-policy. By
using the guide-policy to form a curriculum of starting states for the
exploration-policy, we are able to efficiently improve performance on a set of
simulated robotic tasks. We show via experiments that JSRL is able to
significantly outperform existing imitation and reinforcement learning
algorithms, particularly in the small-data regime. In addition, we provide an
upper bound on the sample complexity of JSRL and show that with the help of a
guide-policy, one can improve the sample complexity for non-optimism
exploration methods from exponential in horizon to polynomial.Comment: 20 pages, 10 figure
The IR Compactness of Dusty Galaxies Set Star-formation and Dust Properties at z~0-2
Surface densities of gas, dust and stars provide a window into the physics of
star-formation that, until the advent of high-resolution
far-infrared/sub-millimeter observations, has been historically difficult to
assess amongst dusty galaxies. To study the link between infrared (IR) surface
densities and dust properties, we leverage the Atacama Large
Millimetre/Submillimetre Array (ALMA) archive to measure the extent of cold
dust emission in 15 IR selected galaxies selected on the basis of
having available mid-IR spectroscopy from Spitzer. We use the mid-IR spectra to
constrain the relative balance between dust heating from star-formation and
active galactic nuclei (AGN), and to measure emission from Polycylic Aromatic
Hydrocarbons (PAHs) -- small dust grains that play a key role in the
photoelectric heating of gas. In general, we find that dust-obscured
star-formation at high IR surface densities exhibits similar properties at low-
and high-redshift, namely: local luminous IR galaxies have comparable PAH
luminosity to total dust mass ratios as high- galaxies, and star-formation
at is more efficient at high IR surface densities despite the fact
that our sample of high galaxies are closer to the main-sequence than local
luminous IR galaxies. High star-formation efficiencies are coincident with a
decline in the PAH/IR luminosity ratio reminiscent of the deficit observed in
far-infrared fine-structure lines. Changes in the gas and dust conditions
arising from high star-formation surface densities might help drive the
star-formation efficiency up. This could help explain high efficiencies needed
to reconcile star-formation and gas volume densities in dusty galaxies at
cosmic noon.Comment: 18 pages, 10 figures, accepted to Ap
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