A complex network of pathways coordinates nodulation and epidermal root hair infection in the symbiotic interaction between rhizobia and legume plants. Whereas nodule formation was known to be ...autoregulated, it was so far unclear whether a similar control is exerted on the infection process.
We assessed the capacity of Medicago plants nodulated by Sinorhizobium meliloti to modulate root susceptibility to secondary bacterial infection or to purified Nod factors in split-root and volatile assays using bacterial and plant mutant combinations. Ethylene implication in this process emerged from gas production measurements, use of a chemical inhibitor of ethylene biosynthesis and of a Medicago mutant affected in ethylene signal transduction.
We identified a feedback mechanism that we named AOI (for Autoregulation Of Infection) by which endosymbiotic bacteria control secondary infection thread formation by their rhizospheric peers. AOI involves activation of a cyclic adenosine 3′,5′-monophosphate (cAMP) cascade in endosymbiotic bacteria, which decreases both root infectiveness and root susceptibility to bacterial Nod factors. These latter two effects are mediated by ethylene.
AOI is a novel component of the complex regulatory network controlling the interaction between Sinorhizobium meliloti and its host plants that emphasizes the implication of endosymbiotic bacteria in fine-tuning the interaction.
Naturalists have been fascinated for centuries by animal colors and color patterns. While widely studied at the adult stage, we know little about color patterns in the embryo. Here, we study a trait ...consisting of coloration that is specific to the embryo and absent from postembryonic stages in water striders (Gerromorpha). By combining developmental genetics with chemical and phylogenetic analyses across a broad sample of species, we uncovered the mechanisms underlying the emergence and diversification of embryonic colors in this group of insects. We show that the pteridine biosynthesis pathway, which ancestrally produces red pigment in the eyes, has been recruited during embryogenesis in various extraocular tissues including antennae and legs. In addition, we discovered that this cooption is common to all water striders and initially resulted in the production of yellow extraocular color. Subsequently, 6 lineages evolved bright red color and 2 lineages lost the color independently. Despite the high diversity in colors and color patterns, we show that the underlying biosynthesis pathway remained stable throughout the 200 million years of Gerromorpha evolutionary time. Finally, we identified erythropterin and xanthopterin as the pigments responsible for these colors in the embryo of various species. These findings demonstrate how traits can emerge through the activation of a biosynthesis pathway in new developmental contexts.
Multibeam echo sounders (MBES) have been commonly used over the last decades in hydrography to perform bathymetric measurements with high precision and provide backscatter imagery of the seafloor. ...Although seafloor classification techniques have been recently developed using MBES backscatter imagery, few semi-automated or completely automated methods joining acoustic imagery and bathymetric data to map marine habitats exist today. In order to fill this gap, a pixel-based data treatment process was designed to provide map of marine habitats coupling the rugosity computed from bathymetry and the backscattering data. In this way, a specific rugosity index, called Bathymetric Automated Treatment for the Classification of the Seafloor (BATCLAS), was developed by computing the least square fitting on the bathymetric soundings in order to obtain a metric value of the seascape unevenness. The whole process relies on a software suite specifically created to treat and edit acoustic data from MBES, using classification algorithms based on customisable decision trees. Tested on an acoustic data set acquired along the French Mediterranean coast with a R2Sonic 2022 MBES and validated with field observations, this method allowed to detect and map with accuracy marine habitats such as complex rocky substrates, Posidonia oceanica (L.) Delile seagrass meadows and artificial structures.
This study aims to describe the epidemiology of COVID-19 patients in a Swiss university hospital.
This retrospective observational study included all adult patients hospitalized with a laboratory ...confirmed SARS-CoV-2 infection from March 1 to March 25, 2020. We extracted data from electronic health records. The primary outcome was the need to mechanical ventilation at day 14. We used multivariate logistic regression to identify risk factors for mechanical ventilation. Follow-up was of at least 14 days.
145 patients were included in the multivariate model, of whom 36 (24.8%) needed mechanical ventilation at 14 days. The median time from symptoms onset to mechanical ventilation was 9·5 days (IQR 7.00, 12.75). Multivariable regression showed increased odds of mechanical ventilation with age (OR 1.09 per year, 95% CI 1.03-1.16, p = 0.002), in males (OR 6.99, 95% CI 1.68-29.03, p = 0.007), in patients who presented with a qSOFA score ≥2 (OR 7.24, 95% CI 1.64-32.03, p = 0.009), with bilateral infiltrate (OR 18.92, 3.94-98.23, p<0.001) or with a CRP of 40 mg/l or greater (OR 5.44, 1.18-25.25; p = 0.030) on admission. Patients with more than seven days of symptoms on admission had decreased odds of mechanical ventilation (0.087, 95% CI 0.02-0.38, p = 0.001).
This study gives some insight in the epidemiology and clinical course of patients admitted in a European tertiary hospital with SARS-CoV-2 infection. Age, male sex, high qSOFA score, CRP of 40 mg/l or greater and a bilateral radiological infiltrate could help clinicians identify patients at high risk for mechanical ventilation.
Loss of cell polarity and disruption of tissue organization are key features of tumorigenesis that are intrinsically linked to spindle orientation. Epithelial tumors are often characterized by ...spindle orientation defects, but how these defects impact tumor formation driven by common oncogenic mutations is not fully understood. Here, we examine the role of spindle orientation in adult epidermis by deleting a key spindle regulator, LGN, in normal tissue and in a PTEN-deficient mouse model. We report that LGN deficiency in PTEN mutant epidermis leads to a threefold increase in the likelihood of developing tumors on the snout, and an over 10-fold increase in tumor burden. In this tissue, loss of LGN alone increases perpendicular and oblique divisions of epidermal basal cells, at the expense of a planar orientation of division. PTEN loss alone does not significantly affect spindle orientation in these cells, but the combined loss of PTEN and LGN fully randomizes basal spindle orientation. A subset of LGN- and PTEN-deficient animals have increased amounts of proliferative spinous cells, which may be associated with tumorigenesis. These results indicate that loss of LGN impacts spindle orientation and accelerates epidermal tumorigenesis in a PTEN-deficient mouse model.
A GHz Spintronic-Based RF Oscillator Villard, P.; Ebels, U.; Houssameddine, D. ...
IEEE journal of solid-state circuits,
2010-Jan., 2010, 2010-01-00, 20100101, Letnik:
45, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
A nano-sized oscillator for RF applications is presented which is based on two spintronic effects, the tunneling magnetoresistance (TMR) and the spin momentum transfer torque. The oscillation ...frequency is several GHz and can be tuned by both a DC bias current and an external DC magnetic field. High compactness, high tunability and full compatibility with standard CMOS process make this spin torque nano-oscillator (STNO) a promising candidate for future RF transceivers. The main issues to be addressed are spectral purity and output power. First measurements on a hybrid built connecting the STNO to a dedicated wideband amplifier show that today's performance in terms of power is close to but not yet compatible with telecommunication standard requirements. Using time domain analysis we show that frequency fluctuations are an issue for spectral purity. Frequency synthesis concepts based on STNOs are also discussed.
ObjectivesThe emergence of targeted therapy is changing rheumatoid arthritis (RA) management, but real-world data remain limited. This study aimed to describe real-world RA treatment patterns using ...data from a French national claims database.MethodsThis longitudinal study used the French Permanent Representative Sample (Echantillon Généraliste des Bénéficiaires) claims database. Patients with RA were identified between 2013 and 2017, with treatment patterns, persistence and adherence described.ResultsThe study population included 2553 patients with RA. Disease-modifying antirheumatic drugs (DMARDs) were prescribed for 1512 (59.2%) patients, of whom 721 (47.6%) did not require discontinuation or treatment switch. There were 377 (24.9%) treatment discontinuations and 114 patients (7.5%) switched to a targeted DMARD (biological and synthetic (Janus kinase inhibitor) DMARDs). Among the 2315 patients with RA in 2017, almost half (n=1102, 47.6%) were not treated with a DMARD. Most (85.7%) received symptomatic treatment (analgesics (81.0%), steroids (49.2%), non-steroidal anti-inflammatory drugs (39.5%)). Of the 1142 treatment initiations identified, 713 (62.4%) were conventional synthetic DMARDs (csDMARDs), with methotrexate being the most frequent (n=553, 48.45%). One-year persistence rates varied between 55.9% (49.2–62.0%) for tumour necrosis factor inhibitors, and 63.4% (59.6–67.0%) for csDMARDs. Treatment adherence, assessed through medication possession ratio, varied between 71.9% and 90.8%, with ≥80% being the adherence cut-off. Almost half of DMARD initiations were associated with long-term (>6 months), high-dose oral steroid use (~7 mg/day prednisone equivalent).ConclusionDespite a diverse therapeutic arsenal, there remains a medical need that is not covered by current RA management, which is frequently compensated for by overprescription of steroids.
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