369 research outputs found
The 11 March 2011 Tohoku tsunami wavefront mapping across offshore Southern California
The 11 March 2011 (M_w = 9.0) Tohoku tsunami was recorded by a temporary array of seafloor pressure gauges deployed off the coast of Southern California, demonstrating how dense array data can illustrate and empirically validate predictions of linear tsunami wave propagation characteristics. A noise cross-correlation method was used to first correct for the pressure gauge instrument phase response. Phase and group travel times were then measured for the first arrival in the pressure gauge tsunami waveforms filtered in narrow bands around 30 periods between 200 and 3000 s. For each period, phase velocities were estimated across the pressure gauge array based on the phase travel time gradient using eikonal tomography. Clear correlation was observed between the phase velocity and long-wavelength bathymetry variations where fast and slow velocities occurred for deep and shallow water regions, respectively. In particular, velocity gradients are pronounced at the Patton Escarpment and near island plateaus due to the abrupt bathymetry change. In the deep open ocean area, clear phase velocity dispersion is observed. Comparison with numerically calculated tsunami waveforms validates the approach and provides an independent measure of the finite-frequency effect on phase velocities at long periods
Standard survey methods for estimating colony losses and explanatory risk factors in Apis mellifera
This chapter addresses survey methodology and questionnaire design for the collection of data pertaining to estimation of honey bee colony loss rates and identification of risk factors for colony loss. Sources of error in surveys are described. Advantages and disadvantages of different random and non-random sampling strategies and different modes of data collection are presented to enable the researcher to make an informed choice. We discuss survey and questionnaire methodology in some detail, for the purpose of raising awareness of issues to be considered during the survey design stage in order to minimise error and bias in the results. Aspects of survey design are illustrated using surveys in Scotland. Part of a standardized questionnaire is given as a further example, developed by the COLOSS working group for Monitoring and Diagnosis. Approaches to data analysis are described, focussing on estimation of loss rates. Dutch monitoring data from 2012 were used for an example of a statistical analysis with the public domain R software. We demonstrate the estimation of the overall proportion of losses and corresponding confidence interval using a quasi-binomial model to account for extra-binomial variation. We also illustrate generalized linear model fitting when incorporating a single risk factor, and derivation of relevant confidence intervals
Phylogeography and population genetics of honey bees (Apis mellifera) from Turkey based on COI-COII sequence data
Analysis of the intra-night variability of BL Lacertae during its August 2020 flare
We present an analysis of the photometry of the blazar BL Lacertae on
diverse timescales from mid-July to mid-September 2020. We have used 11
different optical telescopes around the world and have collected data over 84
observational nights. The observations cover the onset of a new activity phase
of BL Lacertae started in August 2020 (termed as the August 2020 flare by us),
and the analysis is focused on the intra-night variability. On short-term
timescales, (i) flux varied with ~2.2\,mag in band, (ii) the spectral index
was found to be weakly dependent on the flux (i.e., the variations could be
considered mildly chromatic) and (iii) no periodicity was detected. On
intra-night timescales, BL Lacertae was found to show bluer-when-brighter
chromatism predominantly. We also found two cases of significant inter-band
time lags of the order of a few minutes. The duty cycle of the blazar during
the August 2020 flare was estimated to be quite high (~90\% or higher). We
decomposed the intra-night light curves into individual flares and determined
their characteristics. On the basis of our analysis and assuming the turbulent
jet model, we determined some characteristics of the emitting regions: Doppler
factor, magnetic field strength, electron Lorentz factor, and radius. The radii
determined were discussed in the framework of the Kolmogorov theory of
turbulence. We also estimated the weighted mean structure function slope on
intra-night timescales, related it to the slope of the power spectral density,
and discussed it with regard to the origin of intra-night variability.Comment: 46 pages, 19 figures, 8 tables, accepted for publication in The
Astrophysical Journal Supplement Series (manuscript version after proof
correction
Current trends in cannulation and neuroprotection during surgery of the aortic arch in Europe†‡
OBJECTIVES To conduct a survey across European cardiac centres to evaluate the methods used for cerebral protection during aortic surgery involving the aortic arch. METHODS All European centres were contacted and surgeons were requested to fill out a short, comprehensive questionnaire on an internet-based platform. One-third of more than 400 contacted centres completed the survey correctly. RESULTS The most preferred site for arterial cannulation is the subclavian-axillary, both in acute and chronic presentation. The femoral artery is still frequently used in the acute condition, while the ascending aorta is a frequent second choice in the case of chronic presentation. Bilateral antegrade brain perfusion is chosen by the majority of centres (2/3 of cases), while retrograde perfusion or circulatory arrest is very seldom used and almost exclusively in acute clinical presentation. The same pumping system of the cardio pulmonary bypass is most of the time used for selective cerebral perfusion, and the perfusate temperature is usually maintained between 22 and 26°C. One-third of the centres use lower temperatures. Perfusate flow and pressure are fairly consistent among centres in the range of 10-15 ml/kg and 60 mmHg, respectively. In 60% of cases, barbiturates are added for cerebral protection, while visceral perfusion still receives little attention. Regarding cerebral monitoring, there is a general tendency to use near-infrared spectroscopy associated with bilateral radial pressure measurement. CONCLUSIONS These data represent a snapshot of the strategies used for cerebral protection during major aortic surgery in current practice, and may serve as a reference for standardization and refinement of different approache
The 11 March 2011 Tohoku Tsunami Wavefront Mapping Across Offshore Southern California
The 11 March 211 (M_w = 9.) Tohoku tsunami was recorded by a temporary array of seafloor pressure gauges deployed off the coast of Southern California, demonstrating how dense array data can illustrate and empirically validate predictions of linear tsunami wave propagation characteristics. A noise cross-correlation method was used to first correct for the pressure gauge instrument phase response. Phase and group travel times were then measured for the first arrival in the pressure gauge tsunami waveforms filtered in narrow bands around 3 periods between 2 and 3 s. For each period, phase velocities were estimated across the pressure gauge array based on the phase travel time gradient using eikonal tomography. Clear correlation was observed between the phase velocity and long-wavelength bathymetry variations where fast and slow velocities occurred for deep and shallow water regions, respectively. In particular, velocity gradients are pronounced at the Patton Escarpment and near island plateaus due to the abrupt bathymetry change. In the deep open ocean area, clear phase velocity dispersion is observed. Comparison with numerically calculated tsunami waveforms validates the approach and provides an independent measure of the finite-frequency effect on phase velocities at long periods.Journal of Geophysical Research: Solid Earth 120(5), 3350-3362. (2015)2169-931
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Targeting miR-181a/b in retinitis pigmentosa: implications for disease progression and therapy
Background
Retinitis pigmentosa (RP) is a genetically heterogeneous group of degenerative disorders causing progressive vision loss due to photoreceptor death. RP affects other retinal cells, including the retinal pigment epithelium (RPE). MicroRNAs (miRs) are implicated in RP pathogenesis, and downregulating miR-181a/b has shown therapeutic benefit in RP mouse models by improving mitochondrial function. This study investigates the expression profile of miR-181a/b in RPE cells and the neural retina during RP disease progression. We also evaluate how miR-181a/b downregulation, by knocking out miR-181a/b-1 cluster in RPE cells, confers therapeutic efficacy in an RP mouse model and explore the mechanisms underlying this process.
Results
Our findings reveal distinct expression profiles, with downregulated miR-181a/b in RPE cells suggesting a protective response and upregulated miR-181a/b in the neural retina indicating a role in disease progression. We found that miR-181a/b-2, encoded in a separate genomic cluster, compensates for miR-181a/b-1 ablation in RPE cells at late time points. The transient downregulation of miR-181a/b in RPE cells at post-natal week 6 (PW6) led to improved RPE morphology, retarded photoreceptor degeneration and decreased RPE aerobic glycolysis.
Conclusions
Our study elucidates the underlying mechanisms associated with the therapeutic modulation of miR-181a/b, providing insights into the metabolic processes linked to its RPE-specific downregulation. Our data further highlights the impact of compensatory regulation between miR clusters with implications for the development of miR-based therapeutics.
Graphical Abstrac
Phylogeography and population genetics of honey bees (Apis mellifera) from Turkey based on COI-COII sequence data
A study that involved DNA sequencing of COI-COII intergenic region of the mitochondrial DNA genome of Apis mellifera honey bees from Turkey was conducted to determine the population genetics and phylogeographic structure of this species from seven distinct areas of Turkey. From the 132 honey bees subjected to DNA sequencing, a total of 12 mitotypes of A. mellifera "C" lineage were observed, of which only one mitotype, C 13, had been reported previously. The most common mitotype, C12, accounted for 47% of the Apis mellifera "C" lineage samples and was found in 13 of the 22 sampled locations. This mitotype was also the basal ancestral mitotype based on TCS spanning tree analysis. The greatest amount of genetic diversity was observed in Bursa, where 4 mitotypes of the A. mellifera "C" lineage were unique to this location. Wright's F-statistics revealed that Artvin and Bursa were the most genetically distinct locations relative to the other sampled locations. Applying a molecular clock, Turkish A. mellifera "C" lineage mitotypes have been diverging for approximately 10,000 to 16,500 yr. based on phylogenetic analysis. In addition, two A. m. syriaca samples were observed from Hatay, Turkey. Phylogenetic analysis which included other A. mellifera subspecies confirms the subspecies relationships of A. mellifera "C" lineage, and A. m. syriaca. this study corroborates other studies that show Turkey to be a reservoir of genetically distinct populations of A. mellifera "C" lineage, which can be useful for developing genetic conservation strategies for A. mellifera
Biallelic variants in ADAMTS15 cause a novel form of distal arthrogryposis
Purpose We aimed to identify the underlying genetic cause for a novel form of distal arthrogryposis. Methods Rare variant family-based genomics, exome sequencing, and disease-specific panel sequencing were used to detect ADAMTS15 variants in affected individuals. Adamts15 expression was analyzed at the single-cell level during murine embryogenesis. Expression patterns were characterized using in situ hybridization and RNAscope. Results We identified homozygous rare variant alleles of ADAMTS15 in 5 affected individuals from 4 unrelated consanguineous families presenting with congenital flexion contractures of the interphalangeal joints and hypoplastic or absent palmar creases. Radiographic investigations showed physiological interphalangeal joint morphology. Additional features included knee, Achilles tendon, and toe contractures, spinal stiffness, scoliosis, and orthodontic abnormalities. Analysis of mouse whole-embryo single-cell sequencing data revealed a tightly regulated Adamts15 expression in the limb mesenchyme between embryonic stages E11.5 and E15.0. A perimuscular and peritendinous expression was evident in in situ hybridization in the developing mouse limb. In accordance, RNAscope analysis detected a significant coexpression with Osr1, but not with markers for skeletal muscle or joint formation. Conclusion In aggregate, our findings provide evidence that rare biallelic recessive trait variants in ADAMTS15 cause a novel autosomal recessive connective tissue disorder, resulting in a distal arthrogryposis syndrome
Qualitative real-time analysis by nurses of sublingual microcirculation in intensive care unit: the MICRONURSE study
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