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Distinct deep subsurface microbial communities in two sandstone units separated by a mudstone layer
Adriana Giongo,Taiana Haag,Renata Medina-Silva,Roberto Heemann,Leandro M. Pereira,Priscilla M. Zamberlan,Fernanda P. Valdez,Rafael R. Oliveira,Eduardo Eizirik,Adriano R. Viana,João Marcelo M. Ketzer 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.3
Deep subsurface microbial communities are more abundant in coarse-grained sedimentary rocks such as sandstones than in fine-grained mudstones. The low porosity and low permeability of mudstones are believed to restrict microbial life. Then, it is expected that distinct, isolated microbial communities may form in sandstones separated by mudstones. In this context, the connectivity between microbial communities in different sandstone units can be investigated to infer evolutionary patterns of diversification in space-time, which may potentially contribute with relevant data for analyses of hydraulic connectivity and stratigraphic correlation. In this work, we used high throughput DNA sequencing of a ribosomal 16S gene fragment to characterize the prokaryotic communities found in Permian sandstone samples of the same core that are separated by one mudstone interval, in the Charqueadas coal field, Parana Basin (Southern Brazil). Our samples were collected at ~300 m deep, in porous sandstones separated by a thick mudstone package. Differences in the bacterial community structure between samples were observed for the classified OTUs, from phylum to genus. Molecular biology might be further applied as a possible tool to help to understand the spatial and temporal distribution of depositional facies, and the efficiency of low permeability rocks to compartmentalize reservoirs. Ongoing studies aim to extend the present investigation into further analyses regarding lateral changes in microbial communities present in the same sandstone units.
GNSS Double Differences Used as Beacon Landing System for Aircraft Instrument Approach
Thomas Dautermann,Bernd Korn,Karin Flaig,Maarten Uijt de Haag 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.6
When using GNSS navigation for final approach guidance of aircraft to a landing site, the only systems currently available are differential GNSS with additional integrity data called augmentation systems. These work well when the landing site is fixed in space and well surveyed. In all other cases, augmentation systems are difficult to use. Here, we propose relative navigation based on GNSS double difference measurement to accomplish the same task, but also onto moving landing platforms or at unsurveyed locations. We call this the Beacon Landing System. Furthermore, we show long term measurement data confirming the sub-meter accuracy and results from flight tests. During the flight test we successfully used the relative navigation for aircraft guidance.
Kang, Jin-Han,Miao, Yan,Lee, SooYoung,Kim, Jong-Hyun,Lee, Kyung-Yil,Ma, Sang Hyuk,Jo, Dae Sun,Song, HyoYoung,Haag, Mendel The Korean Society of Infectious Diseases and Kore 2016 Infection and Chemotherapy Vol.48 No.1
<P><B>Background</B></P><P>This descriptive epidemiological study aimed to assess the prevalence of serum bactericidal antibodies against <I>Neisseria meningitidis</I> serogroups A, C, W and Y in adolescents and adults in the Republic of Korea.</P><P><B>Materials and Methods</B></P><P>In total, 987 subjects aged 11-55 years from five geographical regions of Korea were included in the study. Human serum bactericidal assay (hSBA) was used to measure hSBA titres for serogroups A, C, W and Y. Percentages of subjects with hSBA titres ≥4 and ≥8, geometric mean titres (GMTs), and associated 95% confidence intervals (CIs), were estimated. Analysis was performed for the entire study population and stratified by age group or region. No statistical hypotheses were tested.</P><P><B>Results</B></P><P>The highest percentage of subjects with hSBA titres ≥8 was observed for serogroup W (74%), was similar for serogroups C (34%) and Y (36%), and was lowest for serogroup A (9%). The percentages of subjects with hSBA titres ≥4 were similar to those with hSBA titres ≥8 for all serogroups. GMTs were 2.56 µg/mL (serogroup A), 5.14 µg/mL (serogroup C), 22.63 µg/mL (serogroup W) and 5.28 µg/mL (serogroup Y). Similar trends in GMTs across serogroups were seen for individual regions and age groups. The highest GMTs for serogroups A, W and Y were recorded in the >19-29 years group, and for serogroup C in the >49-55 years group. Across all regions, GMTs were very similar for serogroups A, C and Y, while more variation was seen for serogroup W.</P><P><B>Conclusion</B></P><P>In the Korean population, among <I>Neisseria meningitidis</I> serogroups A, C, W and Y, serum bactericidal antibodies were most prevalent against serogroup W and least prevalent against serogroup A. These trends were maintained across age groups and regions. The highest GMTs for serogroups A, W and Y were observed in the >19-29 years group. The reasons behind the observed differences in prevalence of bactericidal antibodies against the serogroups are currently not understood, although carriage and cross-reactivity of the assay may be important influences.</P>