Search results for "rct"
showing 10 items of 1934 documents
Acidobacteria dominate the active bacterial communities of Arctic tundra with widely divergent winter-time snow accumulation and soil temperatures.
2012
The timing and extent of snow cover is a major controller of soil temperature and hence winter-time microbial activity and plant diversity in Arctic tundra ecosystems. To understand how snow dynamics shape the bacterial communities, we analyzed the bacterial community composition of windswept and snow-accumulating shrub-dominated tundra heaths of northern Finland using DNA- and RNA-based 16S rRNA gene community fingerprinting (terminal restriction fragment polymorphism) and clone library analysis. Members of the Acidobacteria and Proteobacteria dominated the bacterial communities of both windswept and snow-accumulating habitats with the most abundant phylotypes corresponding to subdivision …
Diversity and distribution of marine heterotrophic bacteria from a large culture collection
2020
16 pages, 5 figures, 3 tables, supplementary information https://doi.org/10.1186/s12866-020-01884-7
Comparison of two PCR methods for detection of Leptospira interrogans in formalin-fixed and paraffin-embedded tissues
2012
In this study we compared two polymerase chain reaction (PCR) methods using either 16S ribosomal RNA (rRNA) or 23S rRNA gene primers for the detection of different Leptospira interrogans serovars. The performance of these two methods was assessed using DNA extracted from bovine tissues previously inoculated with several bacterial suspensions. PCR was performed on the same tissues before and after the formalin-fixed, paraffin-embedding procedure (FFPE tissues). The 23S rDNA PCR detected all fresh and FFPE positive tissues while the 16S rDNA-based protocol detected primarily the positive fresh tissues. Both methods are specific for pathogenic L. interrogans. The 23S-based PCR method successfu…
Vulnerability of the North Water ecosystem to climate change
2021
High Arctic ecosystems and Indigenous livelihoods are tightly linked and exposed to climate change, yet assessing their sensitivity requires a long-term perspective. Here, we assess the vulnerability of the North Water polynya, a unique seaice ecosystem that sustains the world’s northernmost Inuit communities and several keystone Arctic species. We reconstruct mid-to-late Holocene changes in sea ice, marine primary production, and little auk colony dynamics through multi-proxy analysis of marine and lake sediment cores. Our results suggest a productive ecosystem by 4400–4200 cal yrs b2k coincident with the arrival of the first humans in Greenland. Climate forcing during the late Holocene, l…
The ABCflux database: Arctic-Boreal CO<sub>2</sub> flux observations and ancillary information aggregated to monthly time…
2021
Abstract. Past efforts to synthesize and quantify the magnitude and change in carbon dioxide (CO2) fluxes in terrestrial ecosystems across the rapidly warming Arctic-Boreal Zone (ABZ) have provided valuable information, but were limited in their geographical and temporal coverage. Furthermore, these efforts have been based on data aggregated over varying time periods, often with only minimal site ancillary data, thus limiting their potential to be used in large-scale carbon budget assessments. To bridge these gaps, we developed a standardized monthly database of Arctic-Boreal CO2 fluxes (ABCflux) that aggregates in-situ measurements of terrestrial net ecosystem CO2 exchange and its derived …
Smoking ban in public places and myocardial infarction hospitalizations in high cardiovascular risk European country – insights from the Polish natio…
2019
Introduction Previous studies demonstrated a possible positive effect of a smoking ban in public places on cardiovascular outcomes. However, little is known about the influence of such regulations in Poland, a country with a high cardiovascular risk. Objectives We aimed to evaluate the association of hospitalization rates for acute myocardial infarction (AMI) in Poland before and after the introduction of the smoking ban in public places in November 2010. Patients and methods The Nationwide Acute Myocardial Infarction Database (AMI‑PL) was searched for the cases of AMI that occurred between 2009 and 2014. The analysis considered sex, age (20-64 years vs 65 years or older), and the place of …
Short communication: Driftwood provides reliable chronological markers in Arctic coastal deposits
2021
Originating from the boreal forest and often transported over large distances, driftwood characterizes many Arctic coastlines. Here we present a combined assessment of radiocarbon (14C) and dendrochronological (ring width) age estimates of driftwood samples to constrain the progradation of two Holocene beach-ridge systems near the Lena Delta in the Siberian Arctic (Laptev Sea). Our data show that the 14C ages obtained on syndepositional driftwood from beach deposits yield surprisingly coherent chronologies for the coastal evolution of the field sites. The dendrochronological analysis of wood from modern drift lines revealed the origin and recent delivery of the wood from the Lena River catc…
[Pharmacological treatment of depression after acute myocardial infarction].
2005
Depressed mood and other depressive symptoms frequently appear after acute myocardial infarction and it is known how these patients have an increased risk for morbidity and mortality compared to patients without depression. Many risk factors promote the development of clinical depression in patients with recent myocardial infarction. Although a large number of studies underline the negative prognostic impact of depression on the infarcted patient, only rarely depressed patients are appropriately diagnosed and treated. Furthermore it should be borne in mind that the use of psychotropics in medically ill patients requires attention. These compounds, in fact, may interact with the disease caus…
Determination of Concentration Profiles of Methyl Mercury Compounds in Surface Waters of Polar and other Remote Oceans by GC-AFD
1998
Abstract The concentration of monomethyl mercury (MeHg+) and dimethyl mercury (Me2Hg) was determined in surface sea-water samples of the Antarctic and Arctic Ocean as well as of other remote areas (South Atlantic and South Pacific) during expeditions of the German research vessel “Polarstern”. A purge and trap/gas chromatographic system, equipped with an atomic fluorescence detector (AFD), was used. For the analysis of MeHg+ conversion into the volatile methylethyl mercury by reaction with tetraethyloborate prior to the purging process was carried out. The detection limit for both methylated mercury compounds was 5 pg Hg/L, which allowed their determination in most ocean water samples even …
Role of computational modeling in thoracic aortic pathology: A review
2014
Thoracic aortic diseases are life-threatening conditions causing significant mortality and morbidity despite advances in diagnostic and surgical treatments. Computational methods combined with imaging techniques provide quantitative information of disease progression, which may improve clinical treatments and therapeutic strategies for clinical practice. Since hemodynamic and wall mechanics play important roles in the natural history and progression of aortic diseases, we reviewed the potential application of computational modeling of the thoracic aorta. We placed emphasis on the clinical relevance of these techniques for the assessment of aortic dissection, thoracic aortic aneurysm, and ao…