An accretion-jet model for M87: interpreting the spectral energy distribution and Faraday rotation measure

M87 is arguably the best supermassive black hole (BH) to explore the jet and/or accretion physics due to its proximity and fruitful high-resolution multi-waveband observations. We model the multi-wavelength spectral energy distribution (SED) of M87 core that observed at a scale of 0.4 arcsec ($\sim 10^5R_{\rm g}$, $R_{\rm g}$ is gravitational radius) as recently presented by Prieto et al. Similar to Sgr A*, we find that the millimeter bump as observed by Atacama Large Millimeter/submillimeter Array (ALMA) can be modeled by the synchrotron emission of the thermal electrons in advection dominated accretion flow (ADAF), while the low-frequency radio emission and X-ray emission may dominantly come from the jet. The millimeter radiation from ADAF dominantly come from the region within $10R_{\rm g}$, which is roughly consistent with the recent very long baseline interferometry observations at 230\,GHz. We further calculate the Faraday rotation measure (RM) from both ADAF and jet models, and find that the RM predicted from the ADAF is roughly consistent with the measured value while the RM predicted from the jet is much higher if jet velocity close to the BH is low or moderate (e.g., $v_{\rm jet}\lesssim0.6\,c$). With the constraints from the SED modeling and RM, we find that the accretion rate close to the BH horizon is $\sim (0.2-1)\times10^{-3}{M}_{\odot} \rm yr^{-1}\ll\dot{\it M}_{\rm B}\sim 0.2\it {M}_{\odot} \rm yr^{-1}$ ($\dot{M}_{\rm B}$ is Bondi accretion rate), where the electron density profile, $n_{\rm e}\propto r^{\sim -1}$, in the accretion flow is consistent with that determined from X-ray observation inside the Bondi radius and recent numerical simulations.Comment: 8 pages, 3 figures, accepted for publication in Ap

TAIWANESE UNIVERSITY STUDENTS’ ATTITUDES TO NON-NATIVE SPEAKERS ENGLISH TEACHERS

Numerous studies have been conducted to explore issues surrounding non-native speakers (NNS) English teachers and native speaker (NS) teachers which concern, among others, the comparison between the two, the self-perceptions of NNS English teachers and the effectiveness of their teaching, and the students’ opinions on and attitudes towards them. Most of these studies have been conducted in ESL contexts in which the teachers are NNS English teachers, while most NNS English teachers actually work in EFL contexts. It is important that we understand issues on NNS English teachers in EFL contexts. Hence, this article aims to investigate university students’ attitudes towards their NNS English teachers in Taiwan. The data were collected through questionnaires and interviews. The findings indicated that Taiwanese students’ attitudes towards their NNS English teachers are positive and favorable and NNS English teachers are generally perceived as capable of delivering efficient instruction though some shortcomings of NNS English teachers were pointed out by participants. Discus- sion on these shortcomings and implications on Taiwan educational system and the qualifications of NNS English teachers is provided.Â

Quality and Cost Matter: Students’ Perceptions of Open versus Non-Open Texts through a Single-Blind Review

Although prior research has examined student perceptions of open materials, research investigating students’ perceptions of open versus copyright-restricted textbooks through a direct, experimental approach is lacking. To better understand how students perceive open textbooks outside the context of the classroom, we examined students’ perceptions of unfamiliar open and non-open (copyright-restricted) psychology textbooks. Forty-four introductory psychology students reviewed chapters from two open textbooks and two traditional/copyrightrestricted textbooks and then ranked the textbooks from most to least favourite. Students rated each chapter on several quality measures, including layout structure, visual appeal, ease of reading, and instructional features. Next, bibliographical information and cost were revealed, and students re-ranked the textbooks accordingly. Before knowing the bibliographic information and cost, students were more likely to prefer the two traditional textbooks. There after, they were more likely to select the open texts. Students often referred to textbook price as a determining factor for their change

Laspeyres Decomposition of Energy Intensity including Household-energy Factors

AbstractIn the previous study papers the change of the total energy intensity is decomposed to the structure factor and the efficiency factor, not considering the household energy factor, because GDP are not made only by household energy. Household energy is about ten percents in the total energy consumption and the household energy of unit GDP are always being decreased. In this paper the change of the total energy intensity is decomposed to the structure adjustment factor, the efficiency factor and the household energy factor. The result of decomposition shows the efficiency factor contribute most to the reduction of total energy intensity from 1985 to 2007, the household energy factor the next, and structure adjustment factor the last. The result of decomposition also explains the causation of the abnormal ascending of total energy intensity from 2002 to 2005

Malaria baseline survey in four special regions of northern Myanmar near China: a cross-sectional study

BACKGROUND: Epidemiological data in the border area of the northern Myanmar near China are either of little accuracy or sparse of information, due to the poor public health system in these areas, and malaria cases may be severely underestimated. This study aimed to investigate malaria prevalence and health facilities for malaria services, and to provide the baseline information for malaria control in these areas. METHODS: A cluster, randomized, cross-sectional survey was conducted in four special regions of northern Myanmar, near China: 5,585 people were selected for a malaria prevalence survey and 1,618 households were selected for a mosquito net-owning survey. Meanwhile, a total of 97 health facilities were surveyed on their malaria services. The data were analysed and descriptive statistics were used. RESULTS: A total of 761 people were found positive through microscopy test, including 290 people for Plasmodium falciparum, 460 for Plasmodium vivax, two for Plasmodium malariae, and nine for mixed infection. The average prevalence of malaria infection was 13.6% (95% CI: 12.7-14.6%). There were significant differences of prevalence of malaria infection among the different regions (P < 0.01); 38.1% (95% CI: 28.3-48.0%) of health facilities had malaria microscope examination service, and 35.1% (95% CI: 25.4-44.7%) of these had malaria treatment services, 23.7% (95% CI: 15.1-32.3%) had malaria outreach services. 28.3% (95% CI: 26.1-30.6%) of households owned one or more long-lasting insecticidal bed nets (LLINs). CONCLUSION: The prevalence of malaria infection was high in the four special regions of northern Myanmar, near China. Malaria services in health facilities in these areas were weak. ITNs/LLINs owning rate was also low. The cross-border cooperation mechanism should be further strengthened to share the epidemical data about malaria, support technical assistance, and conduct joint malaria control or elimination activities

Health-Related Quality of Life in Chinese Patients with Chronic Liver Disease

Aim. To investigate the factors contributing to health-related quality of life (HRQOL) in Chinese patients with chronic liver disease (CLD). Methods. HRQOL was measured with SF-36v2 Chinese version. Demographic and clinical data were collected, and patients with liver cirrhosis were divided into Child's Class A, B, and C according to Child-Turcotte-Pugh scoring system. Results. A total of 392 Chinese patients with CLD and 91 healthy controls were enrolled. HRQOL in patients with CLD was lower than that in healthy controls. Score of PCS in healthy controls was 54.6 ± 5.5 and in CLD was 47.8 ± 8.8 (P = 0.000). Score of MCS in healthy controls was 56.4 ± 8.1 and in CLD was 51.7 ± 7.4 (P = 0.000). Increasing severity of CLD from no cirrhosis to advanced cirrhosis was associated with a decrease on all domains of the SF-36 (P < 0.05). Stepwise linear regression analysis showed that severity of disease, age, present ascites, present varices, and prothrombin time had significant effect on physical health area. Severity of disease, female, present varices, total bilirubin, prothrombin time, and hemoglobin had significant effect on mental health area. Conclusions. Patients with CLD had impaired HRQOL. Increasing severity of CLD was associated with a decrease on HRQOL. Old age, female gender, advanced stage of CLD, present ascites, hyperbilirubinemia, and prolonging prothrombin time were important factors reducing HRQOL

7-[(5,5-Dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)­oxy]-4-methyl-2H-chromen-2-one

The title compound, C15H17O6P, was obtained from a reaction of 4-methyl-7-hy­droxy­coumarin and 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide. There are two mol­ecules in the asymmetric unit in which the benzopyran ring system is almost planar [r.m.s. deviation for each molecule = 0.003 Å]. In the crystal, C—H⋯O hydrogen bonds and π–π stacking inter­actions [with centroid–centroid distances of 3.743 (3) and 3.727 (3) Å] link the two mol­ecules. The dioxaphospho­rinane ring adopts a chair conformation in both asymmetric molecules