Topological and differentiable rigidity of submanifolds in space forms

Let $F^{n+p}(c)$ be an $(n+p)$-dimensional simply connected space form with nonnegative constant curvature $c$. We prove that if $M^n(n\geq4)$ is a compact submanifold in $F^{n+p}(c)$, and if $Ric_M>(n-2)(c+H^2),$ where $H$ is the mean curvature of $M$, then $M$ is homeomorphic to a sphere. We also show that the pinching condition above is sharp. Moreover, we obtain a new differentiable sphere theorem for submanifolds with positive Ricci curvature.Comment: 12 page

Distribution of HNCO 505−404_{05}-4_{04} in Massive Star-forming Regions

The goal of this paper is to study the spatial distribution of HNCO in massive star-forming regions, and investigate its spatial association with infrared sources, as well as physical conditions in region of HNCO emission. We have mapped nine massive star-forming regions in HNCO 5$_{05}-4_{04}$ with the Purple Mountain Observatory 13.7m telescope. The C18O maps of these sources were obtained simultaneously. The HNCO emission shows compact distribution, with emission peak centred on water masers. Nearly all the HNCO clumps show signs of embedded mid-infrared or far-infrared sources. The FWHM sizes of HNCO clumps are significantly smaller than C18O clumps but rather similar to HC3N clumps. We also found good correlation between the integrated intensities, linewidths and LSR velocities of HNCO and HC3N emission, implying similar excitation mechanism of these two species. As such, collisional excitation is likely to be the dominant excitation mechanism for HNCO 5$_{05}-4_{04}$ emission in galactic massive star-forming regions.Comment: 9 pages, 4 figures, accepted by A&

Two Enlightenments on Chinese Literature Going Out: By Comparing Wolf Totem With China in Ten Words

China still has a serious cultural deficit in international cultural exchanges, and few contemporary Chinese literature works are successfully translated and communicated in foreign countries. However, both Wolf Totem and China in Ten Words have been on Amazon’s list of best sellers after their English versions were published in the United Kingdom and the United States. Based on comparison between them, this paper aims to find the similarities and differences between Wolf Totem and China in Ten Words, and then get two enlightenments on Chinese literature going out: First, successful translation and communication of Chinese literature works share some similarities. Successfully finding the similarities will be conductive to Chinese literature going out. Second, not all successful translation and communication of Chinese literature can objectively and truly present China to the world, taking China in Ten Words as an example. Therefore, the Chinese government should play a more active role in sending out Chinese literature works which could construct China’s national image.

Does mobile phone ownership predict better utilization of maternal and newborn health services? a cross-sectional study in Timor-Leste.

BackgroundIncreasingly popular mobile health (mHealth) programs have been proposed to promote better utilization of maternal, newborn and child health services. However, women who lack access to a mobile phone are often left out of both mHealth programs and research. In this study, we determine whether household mobile phone ownership is an independent predictor of utilization of maternal and newborn health services in Timor-Leste.MethodsThe study included 581 women aged 15-49 years with a child under the age of two years from the districts of Manufahi and Ainaro in Timor-Leste. Participants were interviewed via a structured survey of knowledge, practices, and coverage of maternal and child health services, with additional questions related to ownership and utilization of mobile phones. Mobile phone ownership was the exposure variable, and the dependent variables included having at least four antenatal care visits, skilled birth attendance, health facility delivery, a postnatal checkup within 24 h, and a neonatal checkup within 24 h for their youngest child. Logistic regression models were applied to assess for associations.ResultsSixty-seven percent of women reported having at least one mobile phone in the family. Women who had a mobile phone were significantly more likely to be of higher socioeconomic status and to utilize maternal and newborn health services. However, after adjusting socioeconomic factors, household mobile phone ownership was not independently associated with any of the dependent variables.ConclusionEvaluations of the effects of mHealth programs on health in a population need to consider the likelihood of socioeconomic differentials indicated by mobile phone ownership