427 research outputs found
Improving Temporal Resolution in Ambient Noise Monitoring of Seismic Wave Speed
10p.International audienceThe use of ambient seismic noise has been intensively investigated to perform passive tomography at various scales. Besides passive tomography, passive monitoring is another application of seismic noise correlation as was shown by the recent observation of postseismic velocity changes around the San Andreas Fault in Parkfield, California. One of the drawbacks of using ambient noise correlation for passive monitoring is the need to average the correlations over a long time period in order to obtain a sufficient signal-to-noise ratio (SNR) for the phase fluctuations to be measured accurately. For the application to passive monitoring, one wants the possibility of following short-term velocity variations (one day or less) using noise correlation functions calculated on short time windows. Another difficulty may then appear when the spatial distribution of noise sources also evolves with time. The aim of this paper is to introduce an adaptive filter to the Parkfield dataset in order to improve the SNR output of the ambient noise correlation functions. When applied to passive monitoring, the temporal resolution can be increased from 30 days up to 1 day. With this improved temporal resolution, the velocity drop observed at Parkfield is shown to be cosesimic with the September 24, 2004 M_w=6.0 event. The relationship between the measured velocity fluctuations and the time-evolution of the spatial distribution of the noise wavefield is also investigated. Finally, the error bar in the amplitudes of the velocity variations are compared with a theoretical expectation
«âŻDes collections en partageâŻÂ» au musĂ©e de Bretagne. Quand la notion de « communâŻÂ» entre au musĂ©e
Lâobjectif du projet prĂ©sentĂ© ici Ă©tait de faire connaĂźtre, partager, permettre la rĂ©utilisation gratuite, dans le respect des droits des collections et ressources patrimoniales du musĂ©e de Bretagne grĂące Ă un outil numĂ©rique simple et intuitif pour les utilisateurs. Les responsables prĂ©sentent les diffĂ©rentes Ă©tapes de mise en place et dressent un premier bilan dâutilisation de ce portail qui sâinscrit dans une dĂ©marche militante dâouverture des donnĂ©es culturelles
The DEAD-box helicase Ded1 from yeast is an mRNP cap-associated protein that shuttles between the cytoplasm and nucleus
International audienceThe DEAD-box helicase Ded1 is an essential yeast protein that is closely related to mammalian DDX3 and to other DEAD-box proteins involved in developmental and cell cycle regulation. Ded1 is considered to be a translation-initiation factor that helps the 40S ribosome scan the mRNA from the 5 7-methylguanosine cap to the AUG start codon. We used IgG pull-down experiments, mass spectrom-etry analyses, genetic experiments, sucrose gradients , in situ localizations and enzymatic assays to show that Ded1 is a cap-associated protein that actively shuttles between the cytoplasm and the nucleus. NanoLC-MS/MS analyses of purified complexes show that Ded1 is present in both nuclear and cytoplasmic mRNPs. Ded1 physically interacts with purified components of the nuclear CBC and the cytoplasmic eIF4F complexes, and its enzymatic activity is stimulated by these factors. In addition, we show that Ded1 is genetically linked to these factors. Ded1 comigrates with these proteins on sucrose gradients, but treatment with rapamycin does not appreciably alter the distribution of Ded1; thus, most of the Ded1 is in stable mRNP complexes. We conclude that Ded1 is an mRNP cofactor of the cap complex that may function to remodel the different mRNPs and thereby regulate the expression of the mRNAs
Entre droit aux soins et qualité des soins
Depuis le 1er janvier 2000, les personnes rĂ©sidant de maniĂšre stable en France et ayant de faibles ressources bĂ©nĂ©ficient en droit dâune couverture maladie. Quâelles soient Françaises ou Ă©trangĂšres, en situation rĂ©guliĂšre ou non, avec ou sans travail. Dans les faits, des inĂ©galitĂ©s persistent pourtant. La crĂ©ation de prestations non contributives, au cĂŽtĂ© de celles du rĂ©gime gĂ©nĂ©ral, ne garantit pas un mĂȘme accĂšs pour tous aux services de santĂ©. Par ailleurs, la qualitĂ© des soins dispensĂ©s souffre dâune mĂȘme iniquitĂ©. Quand la discrimination devient systĂšme : Ă©tat des lieux
A FieldâCapable Rapid Plant DNA Extraction Protocol Using Microneedle Patches for Botanical Surveying and Monitoring
Premise: A novel protocol for rapid plant DNA extraction using microneedles is proposed, which supports botanic surveys, taxonomy, and systematics. This protocol can be conducted in the field with limited laboratory skills and equipment. The protocol is validated by sequencing and comparing the results with QIAGEN spin-column DNA extractions using BLAST analyses.
Methods and Results: Two sets of DNA extractions were conducted on 13 species spanning various leaf anatomies and phylogenetic lineages: (i) fresh leaves were punched with custom polymeric microneedle patches to recover genomic DNA, or (ii) QIAGEN DNA extractions. Three plastid (matK, rbcL, and trnH-psbA) and one nuclear ribosomal (ITS) DNA regions were amplified and sequenced using Sanger or nanopore technology. The proposed method reduced the extraction time to 1âmin and yielded the same DNA sequences as the QIAGEN extractions.
Conclusions: Our drastically faster and simpler method is compatible with nanopore sequencing and is suitable for multiple applications, including high-throughput DNA-based species identifications and monitoring
Resource allocation by the marine cyanobacterium Synechococcus WH8102 in response to different nutrient supply ratios
Differences in relative availability of nitrate vs. phosphate may contribute to regional variations in plankton elemental stoichiometry. As a representative of the globally abundant marine Synechococcus, strain WH8102 was grown in 16 chemostats up to 52 âd at a fixed growth rate with nitrogenâphosphorus ratios (N : Psupply) of 1â50. Initially, the phosphate and nitrate concentrations in the vessel decreased when the respective nutrient was limiting. Cell growth generally stabilized, although several chemostats had apparent oscillations in biomass. We observed extensive plasticity in the elemental content and ratios. N : Pcell matched the supply values between N : Psupply 5 and 20. The C : Pcell followed a similar trend. In contrast, the mean C : Ncell was 6.8 and did not vary as a function of supply ratios. We also observed that induction of alkaline phosphatase, the fraction of P allocated to nucleic acids, and the lipid sulfoquinovosyldiacylglycerol : phosphatidyglycerol ratio inversely correlated with P availability. Our results suggest that this extensive plasticity in the elemental content and ratios depends both on the external nutrient availability as well as past growth history. Thus, our study provides a quantitative understanding of the regulation of the elemental stoichiometry of an abundant ocean phytoplankton lineage
A user's guide to the local arithmetic of hyperelliptic curves
A new approach has been recently developed to study the arithmetic of
hyperelliptic curves over local fields of odd residue characteristic
via combinatorial data associated to the roots of . Since its introduction,
numerous papers have used this machinery of "cluster pictures" to compute a
plethora of arithmetic invariants associated to these curves. The purpose of
this user's guide is to summarise and centralise all of these results in a
self-contained fashion, complemented by an abundance of examples.Comment: Minor changes. To appear in the Bulletin of the London Mathematical
Societ
Do physical tests have a prognostic value in chronic midportion Achilles tendinopathy?
Objectives: To determine whether baseline physical tests have a prognostic value on patient-reported outcomes in Achilles tendinopathy. Design: Prospective cohort study, secondary analysis of data from a randomized trial. Methods: Patients with chronic midportion Achilles tendinopathy performed a progressive calf muscle exercise program. At baseline and after 2, 6, 12 and 24 weeks, patients completed the Victorian Institute of Sports AssessmentâAchilles questionnaire and performed the following physical tests: ankle dorsiflexion range of motion with a bent knee or an extended knee, calf muscle strength, jumping height and pain on palpation (Visual Analogue Scale; 0â100) and after 10 hops (Visual Analogue Scale-10-hops). Associations between baseline test results and improvement (Victorian Institute of Sports AssessmentâAchilles scores) were determined using a Mixed Linear Model. Results: 80 patients were included. The mean Victorian Institute of Sports AssessmentâAchilles score improved 20 points (95 % confidence interval, 16â25, P < .001) after 24 weeks. There were significant associations between the baseline ankle dorsiflexion range of motion with a bent knee (ÎČ 0.2, 95 % confidence interval 0.001 to 0.3, P = .049), the baseline pain provocation tests (Visual Analogue Scale palpation: ÎČ â 0.2; 95 % confidence interval: â 0.4 to â 0.1; P < .001, Visual Analogue Scale-10-hops: ÎČ â 0.3; 95 % confidence interval: â 0.4 to â 0.2; P < .001) and the change in the Victorian Institute of Sports AssessmentâAchilles score. Conclusions: In patients with chronic midportion Achilles tendinopathy, easy-to-perform pain provocation tests have a clinically relevant prognostic value on patient-reported improvement. Patients with less pain during pain provocation tests at baseline have a better improvement in pain, function and activities after 24 weeks than patients with high baseline pain scores.</p
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