39 research outputs found
Ultralow noise C + L wideband WDM-IMDD transmission at 18 × 112 Gbps by using hybrid second-order distributed Raman and first-order lumped Raman amplification
We experimentally investigated and demonstrated an ultralow noise hybrid amplifier that combines second-order distributed Raman amplifier (DRA) and first-order lumped Raman amplifier (LRA) in a cascaded approach. This approach allows for the reutilization of pump light from the LRA as the seed light in the second-order DRA, and simultaneous full-band dispersion compensation is realized by using dispersion compensation fiber in the LRA. This approach also supports broadband gain flattening based on the separated DRA and LRA configuration. The transmission application of the proposed amplifier was investigated using a set of 10 external cavity lasers (ECLs) in the C-band and 8 ECLs in the L-band. Ranging from 1531.12 nm to 1595.49 nm across C + L band, the proposed hybrid amplifier gives a maximum on-off gain of 27.2 dB and an average gain of 23.4 dB, with an extremely low effective noise figure (NF) of lower than -2.9 dB. Intensity modulation direct detection (IMDD) signal transmission is carried out at two different data rates across these 18 wavelengths in the C + L band: (1) 56 Gbps/λ PAM-4 signal; (2) 112 Gbps/λ PAM-4 signal. The results show that the error free transmissions are demonstrated over 101.6 km EX2000 fiber using both signals with 7% HD-FEC and 20% SD-FEC, respectively
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Global land surface temperature influenced by vegetation cover and PM2.5 from 2001 to 2016
Land surface temperature (LST) is an important parameter to evaluate environmental changes. In this paper, time series analysis was conducted to estimate the interannual variations in global LST from 2001 to 2016 based on moderate resolution imaging spectroradiometer (MODIS) LST, and normalized difference vegetation index (NDVI) products and fine particulate matter (PM2.5) data from the Atmospheric Composition Analysis Group. The results showed that LST, seasonally integrated normalized difference vegetation index (SINDVI), and PM2.5 increased by 0.17 K, 0.04, and 1.02 �g/m3 in the period of 2001–2016, respectively. During the past 16 years, LST showed an increasing trend in most areas, with two peaks of 1.58 K and 1.85 K at 72�N and 48�S, respectively. Marked warming also appeared in the Arctic. On the contrary, remarkable decrease in LST occurred in Antarctic. In most parts of the world, LST was affected by the variation in vegetation cover and air pollutant, which can be detected by the satellite. In the Northern Hemisphere, positive relations between SINDVI and LST were found; however, in the Southern Hemisphere, negative correlations were detected. The impact of PM2.5 on LST was more complex. On the whole, LST increased with a small increase in PM2.5 concentrations but decreased with a marked increase in PM2.5. The study provides insights on the complex relationship between vegetation cover, air pollution, and land surface temperature
Relationship between occupational stress, job burnout, and depressive symptoms among workers in an automobile manufacturing enterprise in Guangzhou
BackgroundThe operation mode of automobile manufacturing industry (AMI) makes workers have different degrees of occupational stress and burnout, which may lead to negative emotions and depressive symptoms. ObjectiveTo study the relationship between occupational stress, job burnout, and depressive symptoms in AMI workers. MethodsIn this study, 1300 workers from a Guangzhou AMI company were selected as subjects by cluster random sampling method. Occupational stress, job burnout, and depressive symptoms of the workers were assessed by using the Effort-Reward Imbalance (ERI) questionnaire, the Maslach Burnout Inventory general survey questionnaire, and the Patient Health Questionnaire-9, respectively. Hierarchical regression was used to analyze the effects of occupational stress and job burnout on depressive symptoms in AMI workers. Mediating effect model was used to analyze the mediating effect of job burnout on the relationship between occupational stress and depressive symptoms. ResultsThere were 1300 questionnaires distributed, 1228 valid questionnaires collected, with a 94.5% recovery rate. The ERI ratio of 1228 AMI workers was 1.06±0.72, and the positive rate of occupational stress was 37.3% (458/1228). The score of job burnout was 2.18±1.37, and the positive rate of job burnout was 62.6% (769/1228). The score of depressive symptoms was 10.27±6.42, and the positive rate of depressive symptoms was 47.1% (578/1228). The dimensional scores of effort and over-commitment in occupational stress as well as emotional exhaustion and depersonalization in job burnout of AMI workers were positively correlated with the depressive symptom scores (rs=0.415, 0.571, 0.573, 0.593, P<0.05). The dimensional scores of reward and personal achievement were negatively correlated (rs=−0.454, −0.339, P<0.05). The percentages of variance in depressive symptoms score explained by occupational stress and job burnout were 26.7% and 16.6%, respectively. Job burnout had a partial mediating effect between the three dimensions of occupational stress and depressive symptoms, and the mediating effect values were −0.2832 (95%CI: −0.3250– −0.2434), 0.3553 (95%CI: 0.3071–0.4041), and 0.4193 (95%CI: 0.3681–0.4725), respectively. ConclusionAMI workers' occupational stress affects job burnout, but also indirectly affects depressive symptoms. Job burnout partially mediates the association between occupational stress and depressive symptoms. Reducing occupational stress and burnout levels of AMI workers may alleviate depressive symptoms
Co-delivery of siRNAs and anti-cancer drugs using layered double hydroxide nanoparticles
In this research we employed layered double hydroxide nanoparticles (LDHs) to simultaneously deliver an anticancer drug 5-fluorouracil (5-FU) and Allstars Cell Death siRNA (CD-siRNA) for effective cancer treatment. The strategy takes advantage of the LDH anion exchange capacity to intercalate 5-FU into its interlayer spacing and load siRNA on the surface of LDH nanoparticles. LDH nanoparticles have been previously demonstrated as an effective cellular delivery system for 5-FU and siRNA separately in various investigations. More excitedly, the combination of CD-siRNA and anticancer drug 5-FU with the same LDH particles significantly enhanced cytotoxicity to three cancer cell lines, e.g. MCF-7, U2OS and HCT-116, compared to the single treatment with either CD-siRNA or 5-FU. This enhancement is probably a result of coordinate mitochondrial damage process. Thus, the strategy to co-deliver siRNA and an anticancer drug by LDHs has great potential to overcome the drug resistance and enhance cancer treatment
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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The Careers of the Blind in Tokugawa Japan, 1603-1868
The blind deviate from bodily ideals and how we make sense of this difference matters. My dissertation examines the blind in Tokugawa Japan (1603–1868) to offer a contrasting perspective on disability from a non-Western society. The blind were impaired but not disabled. They were, in fact, enabled and engaged in careers that were mostly unthinkable to their peers in other contemporary societies.
By far the most important enabling factor was the growth of a core institution called the tôdôza. I focus on the main professions through which the blind made their living—musical performance, moneylending, and medicine—and their relationships with the tôdôza. In my discussion, I investigate surprising aspects of the careers of the blind. These characteristics not only reflect the complex social history of the blind, but also reveal the intersections with critical developments in Tokugawa society.
Founded as a society of blind musicians, the tôdôza was transformed into a political institution and later, a profit-driven organization of diverse professions. The narrative analyzes the social, political, and economic contexts of this transformation. Chapter one discusses the hierarchy of the tôdôza and the financial motives of moneylending. Chapter two looks at how rituals and myths were appropriated to strengthen the internal authority of the tôdôza. In chapter three, I discuss the representative lyrical genre of blind musicians called heikyoku and the increasing participation of sighted performers in writing texts. In chapter four, I explore how popular discourses about health compelled the tôdôza to innovate and concentrate on medical practice.
My dissertation takes a fresh approach to Japanese history with insights from disability studies. The tôdôza supported the formation of blind communities and gave them political and economic leverage. This reverse perspective places the blind not on the margins, but instead refocuses the attention on their leading roles in transforming Tokugawa society. The history of disability in early modern Japan is also about the history of the tôdôza. By focusing on the tôdôza, my proposed approach highlights that the discourse of disability embraces the underemphasized but nonetheless important theme of enablement, which is crucial for retelling Japanese history.East Asian Languages and Civilization