354 research outputs found

    The spatial distribution patterns of rainfall use efficiency (RUE) of evergreen coniferous forests in Chinese subtropical zone

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    Rainfall use efficiency (RUE) of subtropics evergreen coniferous forests and RUE spatial patterns in Chinese subtropical zone were estimated. RUE and ecosystem net primary productivity (NPP) spatial distribution, as well as the relationship between RUE and rainfall were particularly focused. RUE of subtropical evergreen coniferous forests and the spatial patterns were estimated based on the data collected from the related weather stations and peer-reviewed literatures. In our study, a gradually increasing tendency of NPP from northwestern to southeastern part of the subtropical zone is observed. No significant differences in RUE among these tree species are visible. RUE of the evergreen coniferous forests reduces as the rainfall increases. RUE reaches the peak when rainfall is less than 700 mm. However, the distribution of RUE is not evident. In linear regression, longitude, latitude, and PAR account for approximately 1.4% of the variability in RUE. These findings suggest that the RUE of evergreen coniferous forests in southern China has a functional convergence

    An analytic derivation of the empirical correlations of gamma-ray bursts

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    Empirical correlations between various key parameters have been extensively explored ever since the discovery of gamma-ray bursts (GRBs) and have been widely used as standard candles to probe the Universe. The Amati relation and the Yonetoku relation are two good examples, which have been paid special attention to. The former reflects the connection between the peak photon energy (Ep) and the isotropic γ\gamma-ray energy release (Eiso), while the latter links Ep with the isotropic peak luminosity (Lp), both in the form of a power law function. Most GRBs are found to well follow these correlations, but a theoretical interpretation is still lacking. Meanwhile, there are also some obvious outliers, which may be off-axis GRBs and may follow different correlations as compared with the on-axis ones. Here we present a simple analytical derivation for the Amati relation and the Yonetoku relation in the framework of the standard fireball model, the correctness of which are then confirmed by numerical simulations. The off-axis Amati relation and Yonetoku relation are also derived, which differ from the corresponding on-axis relation markedly. Our results reveal the intrinsic physics lying behind the radiation processes of GRBs, and highlight the importance of viewing angle in the empirical correlations of GRBs.Comment: 20 pages, 7 figures, 2 tables. Submitted to A&

    2-Ferrocenyl-3-meth­oxy-6-methyl­pyridine

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    In the title compound, [Fe(C5H5)(C12H12NO)], the dihedral angle between the pyridyl and substituted cyclo­penta­dienyl rings is 23.58 (3)°. The crystal structure is characterized by weak inter­molecular C—H⋯N hydrogen-bonding contacts, leading to the formation of chains running parallel to the n-glide planes. A weak inter­molecular C—H⋯π contact is also present

    Serum γ-glutamyltransferase and uric acid levels are associated with impaired fasting glucose in adults from Inner Mongolia, China

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    BACKGROUND: Serum γ-glutamyltransferase (GGT) and uric acid (UA) levels are elevated in patients with diabetes or cardiovascular disease. Prediabetes, characterized by impaired glucose tolerance, is an important risk factor for overt diabetes as well as cardiovascular disease. Therefore, the aim of this study was to explore the relationship between GGT, UA and prediabetes in a Chinese population, and provide a scientific basis for the early prevention and treatment of diabetes. METHODS: We performed a cross-sectional population-based study in a cohort of 2694 subjects (1211 men and 1483 women, aged 35–86 years). Questionnaires and physical examinations were performed using standardized procedures. Fasting blood was collected to measure glucose and other biochemical parameters. The subjects were divided into two groups with either normal fasting glucose (NFG) or impaired fasting glucose (IFG), according to international diagnostic criteria. Logistic regression analysis was performed to estimate odds ratios (OR) and 95% confidence intervals. RESULTS: Compared with the NFG group, the IFG group had significantly higher blood pressure but lower high-density lipoprotein–cholesterol in women. Body mass index, waist circumference, triglyceride, glucose, GGT, and UA levels were significantly higher in males and females in the IFG group than those in the NFG group. Logistic regression analysis revealed that the OR for prediabetes increased with increasing serum GGT quartiles and UA quartiles. GGT and UA were positively associated with prediabetes in men and women, independent of age, ethnicity, smoking, alcohol consumption, blood pressure, physical labor, and other confounders. CONCLUSIONS: We found that serum GGT and UA levels were positively associated with prediabetes in men and women living in areas inhabited by Chinese ethnic minorities. As elevated GGT and UA levels were associated with significantly increased risk of prediabetes, they may be used as sensitive biological markers of prediabetes

    Factors Associated with Myopia in School Children in China: The Beijing Childhood Eye Study

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    Purpose: To assess factors associated with myopia in school children in rural and urban parts of Greater Beijing. Methods: The Beijing Pedriatic Eye Study was a population-based cross-sectional study, in which one school of each level (primary, junior high, senior high) was randomly selected from nine randomly selected districts out of 18 districts of Greater Beijing. The children underwent non-cylcoplegic refractometry and their parents an interview. Results: Of 16,771 eligible students, 15,066 (89.8%) children (7,769 (51.6%) girls) participated, with 8,860 (58.8%) participants living in the rural region. Mean age was 13.263.4 years (range:7–18 years). In multivariate analysis, prevalence of myopia (defined as #21.00 diopters) was associated with higher age (Odds ratio(OR):1.37; 95% confidence interval(CI):1.35,1.39), female gender (OR:1.35;95%CI:1.25,1.47), key school type (OR:0.77;95%CI: 0.70,0.85), higher family income (OR:1.04;95%CI:1.01,1.07), parental myopia (OR:1.46;95%CI:1.40,1.53), dim reading illumination (OR:0.93;95%CI: 0.88,0.98), longer daily studying duration (OR:1.10;95%CI:1.06,1.15), shorter duration of watching television (or computer) (OR:0.93;95%CI:0.89,0.97), higher self-reported protein intake (OR:0.94;95%CI:0.90,0.99), feeling well about life and status (OR:0.93;95%CI:0.89,0.98), and feeling tired or dizzy (OR:0.94;95%CI:0.91,0.97). Prevalence of high myopia (defined as #26.00 diopters) was associated with higher age (OR:1.43;95%CI:1.38, 1.48), key school type (OR:0.61;95%CI:0.49,0.74), family income (OR:1.07;95%CI:1.02,1.13), parental myopia (OR:1.65;95%CI:1.54,1.76), dim reading illumination (OR:0.86;95%CI:0.77,0.96), less rest during studying (OR:1.18;95%CI:1.10,1.27), feeling well about life and studying (OR:0.88;95%CI: 0.81,0.96) and feeling dizzy or tired (OR:0.93;95%CI:0.87,0.99). Prevalence of high myopia (defined as #28.00 diopters) was significantly associated with higher age (OR:1.39;95%CI:1.31,1.48;), key school type (OR:0.61;95%CI:0.42,0.88) and parental myopia (OR:1.87;95%CI:1.66,2.12). Conclusions: Myopia in school children in Greater Beijing was associated with higher age, female gender, school type, parental myopia, higher socioeconomic background, dim reading illumination, longer daily studying duration, less rest during study, shorter duration of watching television (or computer), higher self-reported protein intake, feeling well about life and status, and feeling tired and dizzy

    Pemodelan Pertumbuhan Ekonomi Indonesia Menggunakan Data Panel Dinamis Dengan Pendekatan Generalized Method of Moment Arellano-Bond

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    Pertumbuhan ekonomi merupakan Perubahan aktivitas perekonomian dalam menghasilkan tambahan pendapatan masyarakat suatu negara dalam periode tertentu. Variabel-variabel ekonomi bersifat dinamis sehingga pada penelitian ini digunakan pemodelan menggunakan metode regresi data panel dinamis. Metode regresi data panel dinamis tidak hanya untuk mengetahui efek jangka pendek (short-run effect), namun juga efek jangka panjang (long-run effect). Faktor-faktor yang diduga mempengaruhi pertumbuhan ekonomi di Indonesia adalah investasi luar negeri, pengeluaran pemerintah dan penyerapan tenaga kerja. Berdasarkan hasil analisis estimasi Generalized Method of Moment (GMM) Arellano-Bond, variabel yang berpengaruh signifikan terhadap pertumbuhan ekonomi adalah investasi luar negeri dan pengeluaran pemerintah. Selanjutnya mendapatkan pemodelan dan mengetahui elastisitas jangka pendek dan jangka panjang. Elastisitas jangka pendek investasi luar negeri sebesar 0,00269 dan jangka panjang sebesar 0,08661. Hal ini menunjukkan bahwa setiap peningkatan 10 persen investasi luar negeri suatu provinsi, maka akan meningkatkan Produk Domestik Regional Bruto (PDRB) secara jangka pendek sebesar 0,0269 persen dan jangka panjang sebesar 0,8661 persen. Elastisitas jangka pendek pengeluaran pemerintah sebesar 0,00198 dan jangka panjang sebesar 0,06384. Hal ini menunjukkan bahwa setiap peningkatan 10 persen pengeluaran pemerintah suatu provinsi, maka akan meningkatkan PDRB secara jangka pendek sebesar 0,0198 persen dan jangka panjang sebesar 0,6384 persen

    A Chinese Herbal Formula to Improve General Psychological Status in Posttraumatic Stress Disorder: A Randomized Placebo-Controlled Trial on Sichuan Earthquake Survivors

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    Introduction. Posttraumatic stress disorder (PTSD) is accompanied by poor general psychological status (GPS). In the present study, we investigated the effects of a Chinese herbal formula on GPS in earthquake survivors with PTSD. Methods. A randomized, double-blind, placebo-controlled trial compared a Chinese herbal formula, Xiao-Tan-Jie-Yu-Fang (XTJYF), to placebo in 2008 Sichuan earthquake survivors with PTSD. Patients were randomized into XTJYF (n = 123) and placebo (n = 122) groups. Baseline-to-end-point score changes in the three global indices of the Symptom Checklist-90-Revised (SCL-90-R) and rates of response in the SCL global severity index (GSI) were the primary endpoints. A subanalysis of the nine SCL factors and the sleep quality score were secondary endpoints. Results and Discussion. Compared to placebo, the XTJYF group was significantly improved in all three SCL global indices (P = 0.001~0.028). More patients in the XTJYF group reported “much improved” than the placebo group (P = 0.001). The XTJYF group performed significantly better than control in five out of nine SCL factors (somatization, obsessive-compulsive behavior, depression, anxiety, and hostility (P = 0.001~0.036)), and in sleep quality score (P < 0.001). XTJYF produced no serious adverse events. These findings suggest that XTJYF may be an effective and safe treatment option for improving GPS in patients with PTSD
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