A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble

The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population.     

Extract of lotus leaf ( Nelumbo nucifera ) and its active constituent catechin with insulin secretagogue activity

The effect of lotus leaf ( Nelumbo nucifera Gaertn.) on diabetes is unclear. We hypothesized that lotus leaf can regulate insulin secretion and blood glucose levels. The in vitro and in vivo effects of lotus leaf methanolic extract (NNE) on insulin secretion and hyperglycemia were investigated. NNE increased insulin secretion from β cells (HIT-T15) and human islets. NNE enhanced the intracellular calcium levels in β cells. NNE could also enhance phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2 and protein kinase C (PKC), which could be reversed by a PKC inhibitor. The in vivo studies showed that NNE possesses the ability to regulate blood glucose levels in fasted normal mice and high-fat-diet-induced diabetic mice. Furthermore, the in vitro and in vivo effects of the active constituents of NNE, quercetin, and catechin, on glucose-induced insulin secretion and blood glucose regulation were evaluated. Quercetin did not affect insulin secretion, but catechin significantly and dose-dependently enhanced insulin secretion. Orally administered catechin significantly reversed the glucose intolerance in high-fat-diet-induced diabetic mice. These findings suggest that NNE and its active constituent catechin are useful in the control of hyperglycemia in non-insulin-dependent diabetes mellitus through their action as insulin secretagogues.     

內蒙及察北蒙古羊杂交改良研究报告第三号——五一牧場杂交兩代結果

五一牧場位于察哈尔盟(現已併入錫林郭勒盟)的东南部,东經116°,北續48°,海拔1,500公尺以上,面积約有60,000公頃。場境内有閃电河、黑风河和羊腸子河。全場有放牧地44,944公頃,打草地3,000公頃,耕地面积約3,000公頃。根据多倫气象站1955年測定的气象材料、年平均温度1.76℃,最高温度35.4℃,最低温度-33.4℃,冬季时間漫長,全年有五个月的平均温度在零下。年降水量429.5毫米,蒸发量1,507.8毫米,风向多为西北风,全年无霜期105天。适于当地种植的作物有燕麦、莜麦、豌豆、粟、蕎麦和馬鈴薯等。該場屬于干旱草原,按自然情况划分牧場。冬季春季牧場为沙窩地区,屬砂質土壤。夏季牧場为平原地区,屬粘質壤土,带硷性,牧草以禾本科为最多。平原地区多为硷草,沙窩地区为沙丘草,一般草高40厘米,每公頃产下草約750公斤。     

Quantum electronic stability of atomically uniform films

We have studied the structural stability of thin silver films with thicknesses of N = 1 to 15 monolayers, deposited on an Fe(100) substrate. Photoemission spectroscopy results show that films of N = 1, 2, and 5 monolayer thicknesses are structurally stable for temperatures above 800 kelvin, whereas films of other thicknesses are unstable and bifurcate into a film with N +/- 1 monolayer thicknesses at temperatures around 400 kelvin. The results are in agreement with theoretical predictions that consider the electronic energy of the quantum well associated with a particular film thickness as a significant contribution to the film stability.     

Antimicrobial susceptibility and plasmid analysis of Actinobacillus pleuropneumoniae isolated in Taiwan.

Sixty Actinobacillus pleuropneumoniae (App) strains from pigs in Taiwan were examined. Serotyping revealed that these belonged to serovars 1 (n=53), 2 (n=3), and 5 (n=4). Agar disk diffusion susceptibility testing of the isolates showed 55 (92%) were resistant to three or more antimicrobial agents. Six resistance patterns were observed. Ampicillin-chloramphenicol-flumequine-nalidixic acid-streptomycin-sulfonamide/trimethoprim-tetracycline was the most common multi-resistance pattern. Minimal inhibitory concentration of 14 antimicrobial agents was determined. The isolates were highly susceptible to ceftiofur and trimethoprim in vitro. Isolates were resistant to streptomycin, ampicillin, and nalidixic acid. All isolates were examined for the presence of plasmids using the alkaline lysis method. Forty three (72%) isolates had four plasmid bands with an approximate sizes of 3.5, 4.3, 5.8 and 6.0 kb; 12 (20%) had three bands at 3.5, 4.3 and 5.2 kb, and 5 (8%) had no plasmid bands. Antimicrobial resistance plasmids were detected in resistant strains of App. Three antimicrobial resistance plasmids were transformed into E. coli DH5 alpha. pTMY1 (4.3 kb) encoded a streptomycin kinase and a dihydropteroate synthase; pTMY2 (6.0 kb) encoded ROB-1 beta-lactamase and aminoglycoside 3'-phosphotransferase; pTMY3 (5.2 kb) encoded only ROB-1 beta-lactamase. The 4.3 kb plasmid was sequenced and consisted of 4242 bp with 42.9% GC content. The 4.3 kb plasmid DNA sequence was 98% homologous to a plasmid previously isolated from Pasteurella haemolytica.     

Sensitivity analysis of SWAT nitrogen simulations with and without in-stream processes

The Soil and Water Assessment Tool (SWAT) has been widely used to estimate pollutant losses from various agricultural management practices. Although many studies have shown good performance in simulating total nitrogen (TN) and dissolved nitrogen (N), the model performed poorly in many other applications, particularly on dissolved N. Poor performance on dissolved N could be attributed to landscape (in-field) processes and/or in-stream N processes in the model. Therefore, the overall goal of this study was to evaluate SWAT N simulations with in-stream processes and without in-stream processes. Sensitivity analysis results showed that when in-stream processes were not simulated, denitrification threshold water content (SDNCO), N in rainfall (RCN) and N percolation coefficient (NPERCO) were the most sensitive parameters to dissolved N losses. However, when in-stream processes were simulated, the most sensitive parameters changed to initial organic N concentration in soil layers (SOLORGN) and organic N enrichment ratio (ERORGN); and the impact of SDNCO, RCN, and NPERCO was greatly decreased. Furthermore, fertilizer timing and amount had little impact on N simulations. SWAT under-estimated dissolved N, but over-estimated organic N and TN. Further calibration could improve the simulation of dissolved N, but would degrade the simulations of organic N and TN.     

The Fermi Gamma-Ray Space Telescope discovers the pulsar in the young galactic supernova remnant CTA 1

Energetic young pulsars and expanding blast waves [supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma-ray sources associated with star-forming regions and SNRs are such young pulsars.     

Expression of a pea disease resistance response gene in the potato cultivar Shepody

The coding sequence from the pea disease resistance response gene 49 (DRR49 gene), was transferred into the potato (Solanum tuberosum L.) cultivar Shepody viaAgrobacterium co-cultivation. Potato leaf explants were co-cultivated withAgrobacterium tumefaciens harboring a binary vector containing the coding sequence from the DRR49 gene under the control of the 35S promoter from cauliflower mosaic virus (CaMV). Transformed potato plants were selected by their resistance to kanamycin. The insertion of foreign DNAs was detected by polymerase chain reaction (PCR) and Southern blot analysis. The expression of DRR49 coding sequence was confirmed via the detection of the corresponding mRNA in northern blot analysis. Field pathogenicity tests indicated that transgenic plants expressing the pea DRR49 mRNA have higher tuber yields than the control plants when grown in PED (potato early dying) infested soil.     

Self-organizing radial basis neural network for predicting typhoon-induced losses to rice

The issue of the typhoon-induced economic losses to rice is investigated. In this study, we propose a hybrid self-organizing radial basis (SORB) neural network for estimating economic losses of rice for the whole Taiwan as well as three sub-regions. The data sets of 143 typhoon events from 1961 to 2008 were collected and analyzed. Data include rice losses and typhoon-related meteorological factors. A number of different input combinations of meteorological and temporal variables are implemented to select the optimal network for predicting the losses, and a two-stage clustering method is used to explore the spatial classification of 15 counties in Taiwan into three sub-regions. The simulation results indicate that the constructed SORB network has a great ability to capture the relationship between typhoon-related variables and rice losses. Furthermore, the SORB model also demonstrates its outstanding reliability and predictability for efficiently providing a valuable reference for counties in Taiwan that could protect farmers from exposure to increasing weather-related risk and accelerate the official decision making process on compensation for rice losses after the invasion of typhoons.