649 research outputs found

    Improved real-time imaging spectrometer

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    An improved AOTF-based imaging spectrometer that offers several advantages over prior art AOTF imaging spectrometers is presented. The ability to electronically set the bandpass wavelength provides observational flexibility. Various improvements in optical architecture provide simplified magnification variability, improved image resolution and light throughput efficiency and reduced sensitivity to ambient light. Two embodiments of the invention are: (1) operation in the visible/near-infrared domain of wavelength range 0.48 to 0.76 microns; and (2) infrared configuration which operates in the wavelength range of 1.2 to 2.5 microns

    Life Table and Consumption Capacity of Corn Earworm,Helicoverpa armigera, Fed Asparagus,Asparagus officinalis

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    The life table and consumption rate of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) reared on asparagus, Asparagus officinalis L. (Asparagales: Asparagaceae) were studied under laboratory conditions to assess their interaction. Development, survival, fecundity, and consumption data were analyzed by the age-stage, twosex life table. This study indicated that asparagus is a natural host of H. armigera. However, the poor nutritional content in asparagus foliage and the poor fitness of H. armigera that fed on asparagus indicated that asparagus is a suboptimal host in comparison to hybrid sweet corn. The uncertainty associated with life table parameters was estimated by using jackknife and bootstrap techniques, and the results were compared for statistical inference. The intrinsic rate of increase ( r ), finite rate of increase ( λ ), net reproductive rate ( R 0), and mean generation time ( T ) were estimated by the jackknife technique to be 0.0780 day (-1) , 1.0811 day (-1) , 67.4 offspring, and 54.8 days, respectively, while those estimated by the bootstrap technique were 0.0752 day (-1) , 1.0781 day (-1) , 68.0 offspring, and 55.3 days, respectively. The net consumption rate of H. armigera , as estimated by the jackknife and bootstrap technique, was 1183.02 and 1132.9 mg per individual, respectively. The frequency distribution of sample means obtained by the jackknife technique failed the normality test, while the bootstrap results fit the normal distribution well. By contrast, the relationship between the mean fecundity and the net reproductive rate, as estimated by the bootstrap technique, was slightly inconsistent with the relationship found by mathematical proof. The application of the jackknife and bootstrap techniques in estimating population parameters requires further examination

    Structural insights into the gating of DNA passage by the topoisomerase II DNA-gate.

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    Type IIA topoisomerases (Top2s) manipulate the handedness of DNA crossovers by introducing a transient and protein-linked double-strand break in one DNA duplex, termed the DNA-gate, whose opening allows another DNA segment to be transported through to change the DNA topology. Despite the central importance of this gate-opening event to Top2 function, the DNA-gate in all reported structures of Top2-DNA complexes is in the closed state. Here we present the crystal structure of a human Top2 DNA-gate in an open conformation, which not only reveals structural characteristics of its DNA-conducting path, but also uncovers unexpected yet functionally significant conformational changes associated with gate-opening. This structure further implicates Top2's preference for a left-handed DNA braid and allows the construction of a model representing the initial entry of another DNA duplex into the DNA-gate. Steered molecular dynamics calculations suggests the Top2-catalyzed DNA passage may be achieved by a rocker-switch-type movement of the DNA-gate

    Who Are Loyal Customers in Online Games

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    Enhanced photo-excitation and angular-momentum imprint of gray excitons in WSe2_{2} monolayers by spin-orbit-coupled vector vortex beams

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    A light beam can be spatially structured in the complex amplitude to possess orbital angular momentum (OAM), which introduces a new degree of freedom alongside the intrinsic spin angular momentum (SAM) associated with circular polarization. Moreover, super-imposing two twisted lights with distinct SAM and OAM produces a vector vortex beam (VVB) in non-separable states where not only complex amplitude but also polarization are spatially structured and entangled with each other. In addition to the non-separability, the SAM and OAM in a VVB are intrinsically coupled by the optical spin-orbit interaction and constitute the profound spin-orbit physics in photonics. In this work, we present a comprehensive theoretical investigation, implemented on the first-principles base, of the intriguing light-matter interaction between VVBs and WSe2_{2} monolayers (WSe2_{2}-MLs), one of the best-known and promising two-dimensional (2D) materials in optoelectronics dictated by excitons, encompassing bright exciton (BX) as well as various dark excitons (DXs). One of the key findings of our study is the substantial enhancement of the photo-excitation of gray excitons (GXs), a type of spin-forbidden dark exciton, in a WSe2_2-ML through the utilization of a twisted light that possesses a longitudinal field associated with the optical spin-orbit interaction. Our research demonstrates that a spin-orbit-coupled VVB surprisingly allows for the imprinting of the carried optical information onto gray excitons in 2D materials, which is robust against the decoherence mechanisms in materials. This observation suggests a promising method for deciphering the transferred angular momentum from structured lights to excitons

    Integrating Chinese Herbal Medicine into Conventional Care Was Related to Lower Risk of Sarcopenia Among Rheumatid Arthritis Patients: A Retrospective, Population-Based Study

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    Objective: Sarcopenia is a frequently observed comorbidity of rheumatoid arthritis (RA) due to the chronic activation of the innate immune system. Accumulating evidence has indicated that Chinese herbal medicine (CHM) safely suppresses proinflammatory pathways and controls inflammation-associated disease, but its effect in reducing the risk of developing sarcopenia among RA subjects has not been established. We conducted a population-level cohort study to compare the sarcopenia risk in patients with RA who use or do not use CHM. Methods: Using claims from a nationwide insurance database, we recruited patients with newly diagnosed RA and without sarcopenia between 2002 and 2010. Propensity score matching was applied to randomly select sets of CHM users and non-CHM users to compare the sarcopenia risk until the end of 2013. The risk of new-onset sarcopenia was assessed using the Cox proportional hazards model. Results: As compared to non-CHM users, those receiving CHM treatment had a lower incidence of sarcopenia (7.69 vs 9.83 per 1000 person-years). CHM was correlated with a decreased chance of sarcopenia after controlling for potential covariates. Notably, use of CHM for more than two years may diminish the risk of getting sarcopenia by about 47% when taken as prescribed. Prescriptions of several herbal formulae may benefit the reduction of sarcopenia risk, such as Yan-Hu-Suo, Bei-Mu, Da-Huang, Huang Qin, Ping-Wei- San (PWS), Shu-Jing-Huo-Xue-Tang (SJHXT) and Chuan-Xiong-Cha-Tiao-San (CXCTS). Conclusion: This study produced new evidence as it is the first to show that the longer duration of CHM use was correlated to reduced risk of sarcopenia in a dose-dependent manner, implying that CHM treatment could be embraced as a routine care strategy for preventing sarcopenia

    Use of Chinese Herbal Medicine Was Related to Lower Risk of Osteoporotic Fracture in Sarcopenia Patients: Evidence from Population-Based Health Claims

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    Introduction: With population aging, sarcopenia and its accompanying risk of osteoporotic fracture has drawn increased attention. Nowadays, while Chinese herbal medicine (CHM) is often used as complementary therapy for many medical conditions, its effect against likelihood of osteoporotic fracture among sarcopenia subjects was not fully elucidated yet. We therefore conducted a population-level study to compare osteoporotic fracture risk for sarcopenia persons with or without CHM use. Methods: Using the patient record from a nationwide insurance database, we recruited persons with newly diagnosed sarcopenia and simultaneously free of osteoporotic fracture between 2000 and 2010. Propensity score matching was then applied to randomly select sets of CHM users and non-CHM users. All of them were tracked until end of 2013 to measure the incidence and adjusted hazard ratios (HRs) for new new-onset fracture in multivariable Cox proportional hazards model. Results: Compared to non-CHM users, the CHM users indeed had a lower incidence of osteoporotic fracture (121.22 vs 156.61 per 1000 person-years). Use of CHM correlated significantly with a lower fracture likelihood after adjusting for potential covariates, and those receiving CHM treatment for more than two years experienced a remarkably lower risk by 73%. Uses of several herbal formulae were correlated to reduced risk of osteoporotic fracture, such as Caulis Spatholobi, Xuduan, Duzhong, Danshen, Shu-Jing-Huo-Xue- Tang, Du-Huo-Ji-Sheng-Tang, Shao-Yao-Gan-Cao-Tang, and Shen-Tong-Zhu-Yu -Tang. Conclusion: Our study depicted that cumulative CHM exposure was inversely associated with osteoporotic fracture risk in a duration-dependent manner, implying that CHM treatment may be embraced as routine care in preventing incident osteoporotic fracture
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