183 research outputs found
Field testing for toxic algae with a microarray: initial results from the MIDTAL project
One of the key tasks in the project MIDTAL (MIcroarrays for the Detection of Toxic ALgae) is to demonstrate the applicability of microarrays to monitor harmful algae across a broad range of ecological niches and toxic species responsible for harmful algal events. Water samples are collected from a series of sites used in national phytoplankton and biotoxin monitoring programmes across Europe. The samples are filtered; the rRNA is extracted, labelled with a fluorescent dye and applied to a microarray chip. The signal intensity from >120 probes previously spotted on the chip is measured and analysed. Preliminary results comparing microarray signal intensities with actual field counts are presented
Field testing for toxic algae with a microarray: initial results from the MIDTAL project
One of the key tasks in MIDTAL (MIcroarrays for the Detection of Toxic ALgae) is to demonstrate
the applicability of microarrays to monitor harmful algae across a broad range of ecological niches
and toxic species responsible for harmful algal events. Water samples are collected from a series of
sites used in national phytoplankton and biotoxin monitoring across Europe. The samples are filtered;
rRNA is extracted, labelled with a fluorescent dye and applied to a microarray chip. The signal
intensity from >120 probes previously spotted on the chip is measured and analysed. Preliminary
results comparing microarray signal intensities with actual field counts are presented.Versión del edito
Evidence of extreme domain wall speeds under ultrafast optical excitation
Time-resolved ultrafast EUV magnetic scattering was used to test a recent
prediction of >10 km/s domain wall speeds by optically exciting a magnetic
sample with a nanoscale labyrinthine domain pattern. Ultrafast distortion of
the diffraction pattern was observed at markedly different timescales compared
to the magnetization quenching. The diffraction pattern distortion shows a
threshold-dependence with laser fluence, not seen for magnetization quenching,
consistent with a picture of domain wall motion with pinning sites. Supported
by simulations, we show that a speed of 66 km/s for highly curved
domain walls can explain the experimental data. While our data agree with the
prediction of extreme, non-equilibrium wall speeds locally, it differs from the
details of the theory, suggesting that additional mechanisms are required to
fully understand these effects.Comment: 5 pages, 4 figures; Supplemental Material: 8 pages, 9 figure
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Complexation of lanthanides, actinides and transition metal cations with a 6-(1,2,4-triazin-3-yl)-2,2’:6’,2’’-terpyridine ligand: implications for actinide(III) /lanthanide(III) partitioning
The quadridentate N-heterocyclic ligand 6-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-2,2’:6’,2’’-terpyridine (CyMe4-hemi-BTBP) has been synthesized and its interactions with Am(III), U(VI), Ln(III) and some transition metal cations have been evaluated by X-ray crystallographic analysis, Am(III)/Eu(III) solvent extraction experiments, UV absorption spectrophotometry, NMR studies and ESI-MS. Structures of the 1:1 complexes with Eu(III), Ce(III) and the linear uranyl (UO22+) ion were obtained by X-ray crystallographic analysis, and showed similar coordination behavior to related BTBP complexes. In methanol, the stability constants of the Ln(III) complexes are slightly lower than those of the analogous quadridentate bis-triazine BTBP ligands, while the stability constant for the Yb(III) complex is higher. 1H NMR titrations and ESI-MS with lanthanide nitrates showed that the ligand forms only 1:1 complexes with Eu(III), Ce(III) and Yb(III), while both 1:1 and 1:2 complexes were formed with La(III) and Y(III) in acetonitrile. A mixture of isomeric chiral 2:2 helical complexes was formed with Cu(I), with a slight preference (1.4:1) for a single directional isomer. In contrast, a 1:1 complex was observed with the larger Ag(I) ion. The ligand was unable to extract Am(III) or Eu(III) from nitric acid solutions into 1-octanol, except in the presence of a synergist at low acidity. The results show that the presence of two outer 1,2,4-triazine rings is required for the efficient extraction and separation of An(III) from Ln(III) by quadridentate N-donor ligand
Relations between lipoprotein(a) concentrations, LPA genetic variants, and the risk of mortality in patients with established coronary heart disease: a molecular and genetic association study
Background:
Lipoprotein(a) concentrations in plasma are associated with cardiovascular risk in the general population. Whether lipoprotein(a) concentrations or LPA genetic variants predict long-term mortality in patients with established coronary heart disease remains less clear.
Methods:
We obtained data from 3313 patients with established coronary heart disease in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. We tested associations of tertiles of lipoprotein(a) concentration in plasma and two LPA single-nucleotide polymorphisms ([SNPs] rs10455872 and rs3798220) with all-cause mortality and cardiovascular mortality by Cox regression analysis and with severity of disease by generalised linear modelling, with and without adjustment for age, sex, diabetes diagnosis, systolic blood pressure, BMI, smoking status, estimated glomerular filtration rate, LDL-cholesterol concentration, and use of lipid-lowering therapy. Results for plasma lipoprotein(a) concentrations were validated in five independent studies involving 10 195 patients with established coronary heart disease. Results for genetic associations were replicated through large-scale collaborative analysis in the GENIUS-CHD consortium, comprising 106 353 patients with established coronary heart disease and 19 332 deaths in 22 studies or cohorts.
Findings:
The median follow-up was 9·9 years. Increased severity of coronary heart disease was associated with lipoprotein(a) concentrations in plasma in the highest tertile (adjusted hazard radio [HR] 1·44, 95% CI 1·14–1·83) and the presence of either LPA SNP (1·88, 1·40–2·53). No associations were found in LURIC with all-cause mortality (highest tertile of lipoprotein(a) concentration in plasma 0·95, 0·81–1·11 and either LPA SNP 1·10, 0·92–1·31) or cardiovascular mortality (0·99, 0·81–1·2 and 1·13, 0·90–1·40, respectively) or in the validation studies.
Interpretation:
In patients with prevalent coronary heart disease, lipoprotein(a) concentrations and genetic variants showed no associations with mortality. We conclude that these variables are not useful risk factors to measure to predict progression to death after coronary heart disease is established.
Funding:
Seventh Framework Programme for Research and Technical Development (AtheroRemo and RiskyCAD), INTERREG IV Oberrhein Programme, Deutsche Nierenstiftung, Else-Kroener Fresenius Foundation, Deutsche Stiftung für Herzforschung, Deutsche Forschungsgemeinschaft, Saarland University, German Federal Ministry of Education and Research, Willy Robert Pitzer Foundation, and Waldburg-Zeil Clinics Isny
A strategic approach to mitigating operational failure across transitions
It is recognized that projects continue to deliver operational assets that are partially defective. This article proposes this because the causes of operational failures have not been extensively analyzed. This study explores how an infrastructure client made quality a strategic and project delivery necessity by undertaking research to analyze operational failure. A mixed-method approach consisting of three phases was used: (1) to understand the operational failure elements; (2) to explore the causes of operational failure; and (3) to develop a new strategic framework to address failure mitigation. The study showed the need for transferring, applying, and recognizing capabilities across strategic business, project delivery, and operational use transitions
Lipoprotein‐Associated Phospholipase A2 Activity Is a Marker of Risk But Not a Useful Target for Treatment in Patients With Stable Coronary Heart Disease
Background: We evaluated lipoprotein‐associated phospholipase A2 (Lp‐PLA2) activity in patients with stable coronary heart disease before and during treatment with darapladib, a selective Lp‐PLA2 inhibitor, in relation to outcomes and the effects of darapladib in the STABILITY trial. Methods and Results: Plasma Lp‐PLA2 activity was determined at baseline (n=14 500); at 1 month (n=13 709); serially (n=100) at 3, 6, and 18 months; and at the end of treatment. Adjusted Cox regression models evaluated associations between Lp‐PLA2 activity levels and outcomes. At baseline, the median Lp‐PLA2 level was 172.4 μmol/min per liter (interquartile range 143.1–204.2 μmol/min per liter). Comparing the highest and lowest Lp‐PLA2 quartile groups, the hazard ratios were 1.50 (95% CI 1.23–1.82) for the primary composite end point (cardiovascular death, myocardial infarction, or stroke), 1.95 (95% CI 1.29–2.93) for hospitalization for heart failure, 1.42 (1.07–1.89) for cardiovascular death, and 1.37 (1.03–1.81) for myocardial infarction after adjustment for baseline characteristics, standard laboratory variables, and other prognostic biomarkers. Treatment with darapladib led to a ≈65% persistent reduction in median Lp‐PLA2 activity. There were no associations between on‐treatment Lp‐PLA2 activity or changes of Lp‐PLA2 activity and outcomes, and there were no significant interactions between baseline and on‐treatment Lp‐PLA2 activity or changes in Lp‐PLA2 activity levels and the effects of darapladib on outcomes. Conclusions: Although high Lp‐PLA2 activity was associated with increased risk of cardiovascular events, pharmacological lowering of Lp‐PLA2 activity by ≈65% did not significantly reduce cardiovascular events in patients with stable coronary heart disease, regardless of the baseline level or the magnitude of change of Lp‐PLA2 activity
Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria
Cyanobacteria are thought to be the main N2-fixing organisms
(diazotrophs) in marine pelagic waters, but recent molecular analyses indicate
that non-cyanobacterial diazotrophs are also present and active. Existing data
are, however, restricted geographically and by limited sequencing depths. Our
analysis of 79,090 nitrogenase (nifH) PCR amplicons encoding
7,468 unique proteins from surface samples (ten DNA samples and two RNA samples)
collected at ten marine locations world-wide provides the first in-depth survey
of a functional bacterial gene and yield insights into the composition and
diversity of the nifH gene pool in marine waters. Great
divergence in nifH composition was observed between sites.
Cyanobacteria-like genes were most frequent among amplicons from the warmest
waters, but overall the data set was dominated by nifH
sequences most closely related to non-cyanobacteria. Clusters related to Alpha-,
Beta-, Gamma-, and Delta-Proteobacteria were most common and showed distinct
geographic distributions. Sequences related to anaerobic bacteria
(nifH Cluster III) were generally rare, but preponderant in
cold waters, especially in the Arctic. Although the two transcript samples were
dominated by unicellular cyanobacteria, 42% of the identified
non-cyanobacterial nifH clusters from the corresponding DNA
samples were also detected in cDNA. The study indicates that non-cyanobacteria
account for a substantial part of the nifH gene pool in marine
surface waters and that these genes are at least occasionally expressed. The
contribution of non-cyanobacterial diazotrophs to the global N2
fixation budget cannot be inferred from sequence data alone, but the prevalence
of non-cyanobacterial nifH genes and transcripts suggest that
these bacteria are ecologically significant
Relations between lipoprotein(a) concentrations, LPA genetic variants, and the risk of mortality in patients with established coronary heart disease: a molecular and genetic association study
BACKGROUND: Lipoprotein(a) concentrations in plasma are associated with cardiovascular risk in the general population. Whether lipoprotein(a) concentrations or LPA genetic variants predict long-term mortality in patients with established coronary heart disease remains less clear. METHODS: We obtained data from 3313 patients with established coronary heart disease in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. We tested associations of tertiles of lipoprotein(a) concentration in plasma and two LPA single-nucleotide polymorphisms ([SNPs] rs10455872 and rs3798220) with all-cause mortality and cardiovascular mortality by Cox regression analysis and with severity of disease by generalised linear modelling, with and without adjustment for age, sex, diabetes diagnosis, systolic blood pressure, BMI, smoking status, estimated glomerular filtration rate, LDL-cholesterol concentration, and use of lipid-lowering therapy. Results for plasma lipoprotein(a) concentrations were validated in five independent studies involving 10 195 patients with established coronary heart disease. Results for genetic associations were replicated through large-scale collaborative analysis in the GENIUS-CHD consortium, comprising 106 353 patients with established coronary heart disease and 19 332 deaths in 22 studies or cohorts. FINDINGS: The median follow-up was 9·9 years. Increased severity of coronary heart disease was associated with lipoprotein(a) concentrations in plasma in the highest tertile (adjusted hazard radio [HR] 1·44, 95% CI 1·14-1·83) and the presence of either LPA SNP (1·88, 1·40-2·53). No associations were found in LURIC with all-cause mortality (highest tertile of lipoprotein(a) concentration in plasma 0·95, 0·81-1·11 and either LPA SNP 1·10, 0·92-1·31) or cardiovascular mortality (0·99, 0·81-1·2 and 1·13, 0·90-1·40, respectively) or in the validation studies. INTERPRETATION: In patients with prevalent coronary heart disease, lipoprotein(a) concentrations and genetic variants showed no associations with mortality. We conclude that these variables are not useful risk factors to measure to predict progression to death after coronary heart disease is established. FUNDING: Seventh Framework Programme for Research and Technical Development (AtheroRemo and RiskyCAD), INTERREG IV Oberrhein Programme, Deutsche Nierenstiftung, Else-Kroener Fresenius Foundation, Deutsche Stiftung für Herzforschung, Deutsche Forschungsgemeinschaft, Saarland University, German Federal Ministry of Education and Research, Willy Robert Pitzer Foundation, and Waldburg-Zeil Clinics Isny
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