5,354 research outputs found
Excitation of high frequency voices from intermediate-mass-ratio inspirals with large eccentricity
The coalescence of a stellar-mass compact object together with an
intermediate-mass black hole, also known as intermediate-mass-ratio inspiral,
is usually not expected to be a viable gravitational wave source for the
current ground-based gravitational wave detectors, due to the generally lower
frequency of such source. In this paper, we adopt the effective-one-body
formalism as the equation of motion, and obtain the accurately calculated
gravitational waveforms by solving the Teukolsky equation in frequency-domain.
We point out that high frequency modes of gravitational waves can be excited by
large eccentricities of intermediate-mass-ratio inspirals. These high frequency
modes can extend to more than 10 Hz, and enter the designed sensitive band of
Advanced LIGO and Advanced Virgo. We propose that such kind of highly eccentric
intermediate-mass-ratio inspirals could be feasible sources and potentially
observable by the ground-based gravitational wave detectors, like the Advanced
LIGO and Advanced Virgo.Comment: 16 pages, 16 figures. Class. Quant. Gravity, accepte
Deep Neural Newsvendor
We consider a data-driven newsvendor problem, where one has access to past
demand data and the associated feature information. We solve the problem by
estimating the target quantile function using a deep neural network (DNN). The
remarkable representational power of DNN allows our framework to incorporate or
approximate various extant data-driven models. We provide theoretical
guarantees in terms of excess risk bounds for the DNN solution characterized by
the network structure and sample size in a non-asymptotic manner, which justify
the applicability of DNNs in the relevant contexts. Specifically, the
convergence rate of the excess risk bound with respect to the sample size
increases in the smoothness of the target quantile function but decreases in
the dimension of feature variables. This rate can be further accelerated when
the target function possesses a composite structure. Compared to other typical
models, the nonparametric DNN method can effectively avoid or significantly
reduce the model misspecification error. In particular, our theoretical
framework can be extended to accommodate the data-dependent scenarios, where
the data-generating process is time-dependent but not necessarily identical
over time. Finally, we apply the DNN method to a real-world dataset obtained
from a food supermarket. Our numerical experiments demonstrate that (1) the DNN
method consistently outperforms other alternatives across a wide range of cost
parameters, and (2) it also exhibits good performance when the sample size is
either very large or relatively limited
Chronic Heat Stress Weakened the Innate Immunity and Increased the Virulence of Highly Pathogenic Avian Influenza Virus H5N1 in Mice
Chronic heat stress (CHS) can negatively affect immune response in animals. In this study we assessed the effects of CHS on host innate immunity and avian influenza virus H5N1 infection in mice. Mice were divided into two groups: CHS and thermally neutral (TN). The CHS treatment group exhibited reduced local immunity in the respiratory tract, including the number of pulmonary alveolar macrophages and lesions in the nasal mucosa, trachea, and lungs. Meanwhile, CHS retarded dendritic cells (DCs) maturation and reduced the mRNA levels of IL-6 and IFN-β significantly (P < .05). After the CHS treatment, mice were infected with H5N1 virus. The mortality rate and viral load in the lungs of CHS group were higher than those of TN group. The results suggest that the CHS treatment could suppress local immunity in the respiratory tract and innate host immunity in mice significantly and moderately increased the virulence in H5N1-infected mice
2-Amino-4-(2-chlorophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile hemihydrate
The asymmetric unit of the title compound, C18H17ClN2O2·0.5H2O, contains two organic molecules and one solvent water molecule. In each organic molecule, the cyclohexene ring adopts an envelope conformation with the C atom connecting the two methyl groups on the flap; the 4H-pyran ring is nearly planar [maximum deviation = 0.113 (3) Å in one molecule and 0.089 (3) Å in the other molecule] and is approximately perpendicular to the chlorophenyl ring [dihedral angle = 86.43 (15)° in one molecule and 89.73 (15)° in the other molecule]. Intermolecular N—H⋯N, N—H⋯O, O—H⋯O and O—H⋯Cl hydrogen bonding is present in the crystal
Size- and speed-dependent mechanical behavior in living mammalian cytoplasm
Active transport in the cytoplasm plays critical roles in living cell physiology. However, the mechanical resistance that intracellular compartments experience, which is governed by the cytoplasmic material property, remains elusive, especially its dependence on size and speed. Here we use optical tweezers to drag a bead in the cytoplasm and directly probe the mechanical resistance with varying size a and speed V. We introduce a method, combining the direct measurement and a simple scaling analysis, to reveal different origins of the size- and speed-dependent resistance in living mammalian cytoplasm. We show that the cytoplasm exhibits size-independent viscoelasticity as long as the effective strain rate V/a is maintained in a relatively low range (0.1 s −1 < V/a < 2 s −1 ) and exhibits size-dependent poroelasticity at a high effective strain rate regime (5 s −1 < V/a < 80 s −1 ). Moreover, the cytoplasmic modulus is found to be positively correlated with only V/a in the viscoelastic regime but also increases with the bead size at a constant V/a in the poroelastic regime. Based on our measurements, we obtain a full-scale state diagram of the living mammalian cytoplasm, which shows that the cytoplasm changes from a viscous fluid to an elastic solid, as well as from compressible material to incompressible material, with increases in the values of two dimensionless parameters, respectively. This state diagram is useful to understand the underlying mechanical nature of the cytoplasm in a variety of cellular processes over a broad range of speed and size scales. Keywords: cell mechanics; poroelasticity; viscoelasticity; cytoplasmic state diagra
Fiber-optic refractometer based on a phase-shifted fiber Bragg grating on a side-hole fiber
A fiber-optic refractive index (RI) sensor based on a π-phaseshifted fiber-Bragg-grating (πFBG) inscribed on a side-hole fiber is presented. The reflection spectrum of the πFBG features two narrow notches associated with the two polarization modes and the spectral spacing of the notches is used for high-sensitivity RI sensing with little temperature cross-sensitivity. The side-hole fiber maintains its outer diameter and mechanical strength. The side-hole fiber is also naturally integrated into a microfluidic system for convenient sample delivery and reduced sample amount. A novel demodulation method based on laser frequency modulation to enhance the sensor dynamic range is proposed and demonstrated
ReactIE: Enhancing Chemical Reaction Extraction with Weak Supervision
Structured chemical reaction information plays a vital role for chemists
engaged in laboratory work and advanced endeavors such as computer-aided drug
design. Despite the importance of extracting structured reactions from
scientific literature, data annotation for this purpose is cost-prohibitive due
to the significant labor required from domain experts. Consequently, the
scarcity of sufficient training data poses an obstacle to the progress of
related models in this domain. In this paper, we propose ReactIE, which
combines two weakly supervised approaches for pre-training. Our method utilizes
frequent patterns within the text as linguistic cues to identify specific
characteristics of chemical reactions. Additionally, we adopt synthetic data
from patent records as distant supervision to incorporate domain knowledge into
the model. Experiments demonstrate that ReactIE achieves substantial
improvements and outperforms all existing baselines.Comment: Findings of ACL 2023, Short Pape
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