6,935 research outputs found
Risk of betel chewing for oesophageal cancer in Taiwan
Among 104 cases of squamous-cell oesophageal carcinoma patients and 277 controls in Taiwan, after adjusting for cigarette smoking, alcohol consumption, and other confounders, we found that subjects who chewed from 1 to 495 betel-year and more than 495 betel-years (about 20 betel quid per day for 20 years) had 3.6-fold (95% Cl = 1.3–10.1) and 9.2-fold risk (95% Cl = 1.8–46.7), respectively, of developing oesophageal cancer, compared to those who did not chew betel. © 2001 Cancer Research Campaign http://www.bjcancer.co
Private schools in the People's Republic of China: Development, modalities and contradictions
Chinese private schools may come across as a contradictory phenomenon: why would an authoritarian and officially socialist government, that needs to rely on education as an instrument of national unification and ideological control, allow for private schools and profit-making in the educational sector? However, seen against the background of the far-reaching privatisation processes that have been shaping the Chinese economy and society since the 1990s, one might equally wonder why this seemingly all-pervading privatisation wave had for a long time stopped short of the educational realm. This chapter outlines the development, modalities, and contradictions of private schools in the People’s Republic of China
Narrowband Biphotons: Generation, Manipulation, and Applications
In this chapter, we review recent advances in generating narrowband biphotons
with long coherence time using spontaneous parametric interaction in monolithic
cavity with cluster effect as well as in cold atoms with electromagnetically
induced transparency. Engineering and manipulating the temporal waveforms of
these long biphotons provide efficient means for controlling light-matter
quantum interaction at the single-photon level. We also review recent
experiments using temporally long biphotons and single photons.Comment: to appear as a book chapter in a compilation "Engineering the
Atom-Photon Interaction" published by Springer in 2015, edited by A.
Predojevic and M. W. Mitchel
Understanding how excess lead iodide precursor improves halide perovskite solar cell performance
The presence of excess lead iodide in halide perovskites has been key for surpassing 20% photon-to-power conversion efficiency. To achieve even higher power conversion efficiencies, it is important to understand the role of remnant lead iodide in these perovskites. To that end, we explored the mechanism facilitating this effect by identifying the impact of excess lead iodide within the perovskite film on charge diffusion length, using electron-beam-induced current measurements, and on film formation properties, from grazing-incidence wide-angle X-ray scattering and high-resolution transmission electron microscopy. Based on our results, we propose that excess lead iodide in the perovskite precursors can reduce the halide vacancy concentration and lead to formation of azimuthal angle-oriented cubic alpha-perovskite crystals in-between 0 degrees and 90 degrees. We further identify a higher perovskite carrier concentration inside the nanostructured titanium dioxide layer than in the capping layer. These effects are consistent with enhanced lead iodide-rich perovskite solar cell performance and illustrate the role of lead iodide
Tag-Aware Recommender Systems: A State-of-the-art Survey
In the past decade, Social Tagging Systems have attracted increasing
attention from both physical and computer science communities. Besides the
underlying structure and dynamics of tagging systems, many efforts have been
addressed to unify tagging information to reveal user behaviors and
preferences, extract the latent semantic relations among items, make
recommendations, and so on. Specifically, this article summarizes recent
progress about tag-aware recommender systems, emphasizing on the contributions
from three mainstream perspectives and approaches: network-based methods,
tensor-based methods, and the topic-based methods. Finally, we outline some
other tag-related works and future challenges of tag-aware recommendation
algorithms.Comment: 19 pages, 3 figure
The evaluation of "Safe Motherhood" program on maternal care utilization in rural western China: a difference in difference approach
BACKGROUND: Maternal care is an important strategy for protection and promotion of maternal and children's health by reducing maternal mortality and improving the quality of birth. However, the status of maternal care is quite weak in the less developed rural areas in western China. It is found that the maternal mortality rates in some western areas of China were 5.8 times higher than those of their eastern costal counterparts. In order to reduce the maternal mortality rates and to improve maternal care in western rural areas of China, the Chinese Ministry of Health (MOH) and the United Nations Children's Fund (UNICEF) sponsored a program named "Safe Motherhood" in ten western provinces of China from 2001 through 2005. This study mainly aims to evaluate the effects of "Safe Motherhood" program on maternal care utilization. METHODS: 32 counties were included in both surveys conducted in 2001 and 2005, respectively. Ten counties of which implemented comprehensive community-based intervention were used as intervention groups, while 22 counties were used as control groups. Stratified 3-stage probability-proportion-to-size sampling method was used to select participating women. Two cross-sectional surveys were conducted with questionnaires about the prenatal care utilization in 2001 and 2005, respectively. Difference in difference estimation was used to assess the effect of intervention on the maternal care utilization while controlling for socio-economic characteristics of women. RESULTS: After the intervention, the proportion of pregnant women who had their first prenatal visit in the first trimester was increased from 38.9% to 76.1%. The proportion of prenatal visits increased from 82.6% to 98.3%. The proportion of women mobilized to deliver in hospitals increased from 62.7% to 94.5%. Hospital delivery was improved greatly from 31.1% to 87.3%. The maternal mortality rate was lowered by 34.9% from 91.76 to 59.74 per 100,000 live births. The community-based intervention had increased prenatal visits rate by 5.2%, first prenatal visit in first trimester rate by 12.0% and hospital delivery rate by 22.5%, respectively. No effect was found on rate of women being mobilized to hospital delivery compared with that of the control group. CONCLUSION: The intervention program seemed to have improved the prenatal care utilization in rural western China
Preparation, structural characterisation and antibacterial properties of Ga-doped sol-gel phosphate-based glass
A sol-gel preparation of Ga-doped phosphate-based glass with potential application in antimicrobial devices has been developed. Samples of composition (CaO)(0.30)(Na2O)(0.20-x) (Ga2O3) (x) (P2O5)(0.50) where x = 0 and 0.03 were prepared, and the structure and properties of the gallium-doped sample compared with those of the sample containing no gallium. Analysis of the P-31 MAS NMR data demonstrated that addition of gallium to the sol-gel reaction increases the connectivity of the phosphate network at the expense of hydroxyl groups. This premise is supported by the results of the elemental analysis, which showed that the gallium-free sample contains significantly more hydrogen and by FTIR spectroscopy, which revealed a higher concentration of -OH groups in that sample. Ga K-edge extended X-ray absorption fine structure and X-ray absorption near-edge structure data revealed that the gallium ions are coordinated by six oxygen atoms. In agreement with the X-ray absorption data, the high-energy XRD results also suggest that the Ga3+ ions are octahedrally coordinated with respect to oxygen. Antimicrobial studies demonstrated that the sample containing Ga3+ ions had significant activity against Staphylococcus aureus compared to the control
Integration of decision support systems to improve decision support performance
Decision support system (DSS) is a well-established research and development area. Traditional isolated, stand-alone DSS has been recently facing new challenges. In order to improve the performance of DSS to meet the challenges, research has been actively carried out to develop integrated decision support systems (IDSS). This paper reviews the current research efforts with regard to the development of IDSS. The focus of the paper is on the integration aspect for IDSS through multiple perspectives, and the technologies that support this integration. More than 100 papers and software systems are discussed. Current research efforts and the development status of IDSS are explained, compared and classified. In addition, future trends and challenges in integration are outlined. The paper concludes that by addressing integration, better support will be provided to decision makers, with the expectation of both better decisions and improved decision making processes
Chemo- and Thermosensory Responsiveness of Grueneberg Ganglion Neurons Relies on Cyclic Guanosine Monophosphate Signaling Elements
Neurons of the Grueneberg ganglion (GG) in the anterior nasal region of mouse pups respond to cool temperatures and to a small set of odorants. While the thermosensory reactivity appears to be mediated by elements of a cyclic guanosine monophosphate (cGMP) cascade, the molecular mechanisms underlying the odor-induced responses are unclear. Since odor-responsive GG cells are endowed with elements of a cGMP pathway, specifically the transmembrane guanylyl cyclase subtype GC-G and the cyclic nucleotide-gated ion channel CNGA3, the possibility was explored whether these cGMP signaling elements may also be involved in chemosensory GG responses. Experiments with transgenic mice deficient for GC-G or CNGA3 revealed that GG responsiveness to given odorants was significantly diminished in these knockout animals. These findings suggest that a cGMP cascade may be important for both olfactory and thermosensory signaling in the GG. However, in contrast to the thermosensory reactivity, which did not decline over time, the chemosensory response underwent adaptation upon extended stimulation, suggesting that the two transduction processes only partially overlap. Copyright (C) 2011 S. Karger AG, Base
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