Karstic geomorphology of carbonate Ouarsenis Piedmont (Boukadir region, Chelif) in Algeria: The role of the Messinian Salinity Crisis

peer reviewedAlgeria displays various karst landscapes due to its diversity in lithology, relief, age and climate. On 16th June 1988, in the northwest of Algeria, a 60 m wide sudden collapse occurred in the Chelif Basin about 1 km north of a marginal carbonate platform. Despite this large event and visible karst dissolutions in the platform, this region has not been classified among the karst areas of Algeria yet. Our study focuses on this Messinian carbonates that form the northern piedmont of the Ouarsenis Mountain range and are covered to the north by Plio-Quaternary deposits. The geological and geomorphological data that we collected reveal that the present-day karstification is limited at the outcropping surface. Present-day carbonate dissolution is impeded by the absence of a topsoil supplying CO2 and by the presence of a calcrete improving the drainage. Although dissolution at depth is generally diffuse due to the porous and friable nature of the carbonates, two factors can, on the contrary, concentrate water infiltration: the presence of a network of more or less subvertical fractures and, occasionally, at the surface, the absence of calcrete, independently of the fracturing nodes There are few ponors and sinkholes present. The endokarst is still present as evidenced by rare caves. In epikarst, solution pipes and shelter caves are prevalent. The later results from differential weathering in relation with the carbonate facies and the progressive calcrete cementation in valleys and slopes during river incision. Near valley bottom, shelters are arranged in steps like terraces. This morphology is related to base-level lowering in relation with the deformation and uplift of the Ouarsenis piedmont. Near the southern edge of the Chelif Basin, deep (>55m) karstic voids are present and associated with paleo-valley incision presently burried by Plio-Quaternary deposits. We interpreted the large 1988 collapse in relation with this paleokarst and propose that its triggering was partly induced by a lowering of the aquifers due to a deficit of precipitation. The deep paleokarst formation and the buried river incision are attributed to the low base-level during the Messinian Salinity Crisis (5.97–5.33 Ma). We evidenced an upper karstic dissolution level filled that is attributed to a per ascendum evolution of the karstic phreatic network in relation with the following Pliocene aggradation

Clinical reappraisal of SHORT syndrome with PIK3R1 mutations: towards recommendation for molecular testing and management

International audienceSHORT syndrome has historically been defined by its acronym: short stature (S), hyperextensibility of joints and/or inguinal hernia (H), ocular depression (O), Rieger abnormality (R) and teething delay (T). More recently several research groups have identified PIK3R1 mutations as responsible for SHORT syndrome. Knowledge of the molecular etiology of SHORT syndrome has permitted a reassessment of the clinical phenotype. The detailed phenotypes of 32 individuals with SHORT syndrome and PIK3R1 mutation, including eight newly ascertained individuals, were studied to fully define the syndrome and the indications for PIK3R1 testing. The major features described in the SHORT acronym were not universally seen and only half (52%) had 4 or more of the classic features. The commonly observed clinical features of SHORT syndrome seen in the cohort included IUGR \textless 10(th) percentile, postnatal growth restriction, lipoatrophy and the characteristic facial gestalt. Anterior chamber defects and insulin resistance or diabetes were also observed but were not as prevalent. The less specific, or minor features of SHORT syndrome include teething delay, thin wrinkled skin, speech delay, sensorineural deafness, hyperextensibility of joints and inguinal hernia. Given the high risk of diabetes mellitus, regular monitoring of glucose metabolism is warranted. An echocardiogram, ophthalmological and hearing assessments are also recommended

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

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

A Multi-Proxy Approach to Reconstruct Hypoxia on the NW Black Sea Shelf over the Holocene

Coastal hypoxia is a worldwide concern. Even though seasonal hypoxia has been reported on the northwestern Black Sea shelf since the 1970s, little is known about oxygenation in this area over the Holocene. With a multiproxy approach, this work aimed to detect potential hypoxic events in two gravity cores. Our results demonstrate that the most common proxies of hypoxia are irrelevant for the Black Sea coastal environment. For instance, the Ammonia-Elphidium index appears to be inappropriate. We assume a salinity bias due to the influence of freshwater inputs. Likely, the redox sensitivity of vanadium is obscured by the dominant supply of detrital elements. However, the size distribution of framboidal pyrites gives clear indications of the oxygenation of the water column. Indeed, the absence of framboidal pyrites in the core located at the Danube mouth suggests permanent oxic conditions over the last 2 ka. On the contrary, in the core located in the Odessa Bay, the two observed ranges of pyrite sizes evidence an alternation between anoxic (mean diameter 3–6 ± 1–2 µm) and hypoxic or oxic (mean diameter 6–10 ± 3–5 µm) conditions in bottom waters over the last 7 ka. Therefore, this proxy reveals different oxygenation levels for these proximal sites

Understanding glass deterioration in museum collections: a multi-disciplinary approach

Raman spectroscopy and secondary ion mass spectrometry were used to investigate chemical and structural changes in soda and soda-lime glass exposed to organic pollutants under ambient and accelerated ageing conditions. Raman spectroscopy reveals modification of the glass structure non-destructively, in situ, and as a function of depth. The pollutants caused growth of crystalline salts and structural changes in the glass surface, with formic and acetic acid more corrosive than formaldehyde

Understanding glass deterioration in museum collections: a multi-disciplinary approach

Raman spectroscopy and secondary ion mass spectrometry were used to investigate chemical and structural changes in soda and soda-lime glass exposed to organic pollutants under ambient and accelerated ageing conditions. Raman spectroscopy reveals modification of the glass structure non-destructively, in situ, and as a function of depth. The pollutants caused growth of crystalline salts and structural changes in the glass surface, with formic and acetic acid more corrosive than formaldehyde