Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

The Effect of Structure and Mechanism of the Hsp70 Chaperone on the Ability to Identify Chemical Modulators and Therapeutics

peer reviewe

Search for factors involved in the rapid shift in watermelon mosaic virus (WMV) populations in south-eastern France

Watermelon mosaic virus (WMV, genus Potyvirus, family Potyviridae) was reported for the first time in France in 1974, and it is now the most prevalent virus in cucurbit crops. In 2000, new strains referred as ‘emerging’ (EM) strains were detected in South-eastern France. EM strains are generally more severe and phylogenetically distinct from those previously reported in this country and referred as ‘classic’ (CL) strains. Since 2000, EM strains have been progressively replacing CL strains in several areas where they co-exist. In order to explain this rapid shift in virus populations, the biological properties of a set of 17 CL and EM WMV isolates were compared. No major differences were observed when comparing a limited host range including 48 different plant species or cultivars. Only two species were differential; Chenopodium quinoa was systemically infected by CL and not by EM isolates whereas Ranunculus sardous was systemically infected by EM and not by CL isolates. A considerable variability was observed in aphid transmission efficiencies but this could not be correlated to the CL or EM types. Two subsets of five isolates of each group were used to compare aphid transmission efficiencies from single and double (CL–EM) infections using six different cucurbit and non-cucurbit hosts. EM isolates were generally better transmitted from mixed CL–EM infections than CL isolates and CL transmission rates were significantly lower from double than from single infections. Cross-protection was only partial between CL and EM strains leading to frequent double infections, and only a slight asymmetry was observed in cross-protection efficiencies. Since double infections occur very commonly in fields, the preferential transmission of EM from mixed CL–EM infections could be one of the factors leading to the displacement of CL isolates by EM isolates

Rapid population shifts in watermelon mosaic virus in France may be related to differential fitness in non-cucurbit hosts

Watermelon mosaic virus (WMV, Potyvirus) is widespread in cucurbit crops in France since its first description 40 years ago. WMV has a relatively wide host range, including several weeds that can constitute winter reservoirs for the virus. Since 2000, new “emerging” (EM) isolates of WMV inducing more severe symptoms, particularly on zucchini squash, were introduced, probably from Asia. Within a few years, they have almost completely replaced in south-eastern France the “classic” (CL) isolates present before. In order to understand the causes for this rapid population shift, we studied the biological properties of CL and EM isolates. There was no evidence for a general better fitness of EM isolates regarding their host range, accumulation and aphid transmission in cucurbit hosts. A modeling approach based on epidemiological data from experimental plots suggested a dissymmetry in favor of EM vs. CL strains regarding their relative capacity of over-infections of plants already infected by the other type of strains, albeit this was not confirmed in greenhouse experimental tests. However, EM isolates appeared to present better aphid transmission rates from some non-cucurbit hosts than CL isolates in conditions of mixed infections, suggesting that non-cucurbit reservoirs could be an important driver of the evolution of viral populations

Search for factors potentially involved in the rapid shift in Watermelon mosaic virus (WMV) populations in south-eastern France

International audienc

Aortopulmonary collaterals in neonates with d-transposition of the great arteries - Clinical significance early after arterial switch operation

OBJECTIVES: Purpose of this study is to evaluate the clinical significance of major aortopulmonary collateral arteries (MAPCAs) during the early postoperative course after arterial switch operation (ASO) in d-transposition of the great arteries (dTGA). METHODS: Clinical data of 98 patients with simple dTGA between January 2007 and December 2016 at the University Children's Hospital Zurich, Switzerland were analyzed retrospectively. RESULTS: 37 from 98 patients (38%) required cardiac catheterization (CC) due to an early complicated postoperative course or difficult coronary transfer due to special coronary anatomy. In 15 (15%) patients, hemodynamically relevant MAPCAs were found during CC and coil embolization was performed. Patients with relevant MAPCAs had a significantly longer PICU stay (7 versus 6 days, p = 0.021), longer hospital stay (41 versus 27 days, p = 0.005), longer mechanical ventilation time (5 versus 3 days, p = 0.005), longer need for inotropic support (5 versus 4 days, p = 0.001) and delayed chest closure time (3 versus 2 days, p = 0.030) in those in whom it was left open in comparison to all other patients. In patients having CC, pre-surgery oxygen saturation was significantly lower in patients with relevant MAPCAs (58% vs 70%, p 0.019). Echocardiography had a sensitivity of 53% and a specificity of 100% in detecting relevant MAPCAs, accurately. CONCLUSIONS: MAPCAs are frequently found in dTGA patients and can be associated with lower baseline oxygen saturation and a prolonged postoperative course after ASO. Transthoracic echocardiography cannot replace CC as diagnostic tool. If significant MAPCAs are suspected, early CC should be performed for diagnostic and therapeutic reasons