Matter-wave laser Interferometric Gravitation Antenna (MIGA): New perspectives for fundamental physics and geosciences

The MIGA project aims at demonstrating precision measurements of gravity with cold atom sensors in a large scale instrument and at studying the associated applications in geosciences and fundamental physics. The first stage of the project (2013-2018) will consist in building a 300-meter long optical cavity to interrogate atom interferometers and will be based at the low noise underground laboratory LSBB in Rustrel, France. The second stage of the project (2018-2023) will be dedicated to science runs and data analyses in order to probe the spatio-temporal structure of the local gravity field of the LSBB region, a site of high hydrological interest. MIGA will also assess future potential applications of atom interferometry to gravitational wave detection in the frequency band $\sim 0.1-10$ Hz hardly covered by future long baseline optical interferometers. This paper presents the main objectives of the project, the status of the construction of the instrument and the motivation for the applications of MIGA in geosciences. Important results on new atom interferometry techniques developed at SYRTE in the context of MIGA and paving the way to precision gravity measurements are also reported.Comment: Proceedings of the 50th Rencontres de Moriond "100 years after GR", La Thuile (Italy), 21-28 March 2015 - 10 pages, 5 figures, 23 references version2: added references, corrected typo

Implementation and testing of the first prompt search for gravitational wave transients with electromagnetic counterparts

Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify and localize GW event candidates and to request images of targeted sky locations. Methods. During two observing periods (Dec 17 2009 to Jan 8 2010 and Sep 2 to Oct 20 2010), a low-latency analysis pipeline was used to identify GW event candidates and to reconstruct maps of possible sky locations. A catalog of nearby galaxies and Milky Way globular clusters was used to select the most promising sky positions to be imaged, and this directional information was delivered to EM observatories with time lags of about thirty minutes. A Monte Carlo simulation has been used to evaluate the low-latency GW pipeline's ability to reconstruct source positions correctly. Results. For signals near the detection threshold, our low-latency algorithms often localized simulated GW burst signals to tens of square degrees, while neutron star/neutron star inspirals and neutron star/black hole inspirals were localized to a few hundred square degrees. Localization precision improves for moderately stronger signals. The correct sky location of signals well above threshold and originating from nearby galaxies may be observed with ~50% or better probability with a few pointings of wide-field telescopes.Comment: 17 pages. This version (v2) includes two tables and 1 section not included in v1. Accepted for publication in Astronomy & Astrophysic

Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts

We outline the scientific motivation behind a search for gravitational waves associated with short gamma ray bursts detected by the InterPlanetary Network (IPN) during LIGO's fifth science run and Virgo's first science run. The IPN localisation of short gamma ray bursts is limited to extended error boxes of different shapes and sizes and a search on these error boxes poses a series of challenges for data analysis. We will discuss these challenges and outline the methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on Gravitational Waves, July 2011, Cardiff, U

Multiparametric determination of genes and their point mutations for identification of beta-lactamases

More than half of all currently used antibiotics belong to the beta-lactam group, but their clinical effectiveness is severely limited by antibiotic resistance of microorganisms that are the causative agents of infectious diseases. Several mechanisms for the resistance of Enterobacteriaceae have been established, but the main one is the enzymatic hydrolysis of the antibiotic by specific enzymes called beta-lactamases. Beta-lactamases represent a large group of genetically and functionally different enzymes of which extended-spectrum beta-lactamases (ESBLs) pose the greatest threat. Due to the plasmid localization of the encoded genes, the distribution of these enzymes among the pathogens increases every year. Among ESBLs the most widespread and clinically relevant are class A ESBLs of TEM, SHV, and CTX-M types. TEM and SHV type ESBLs are derived from penicillinases TEM-1, TEM-2, and SHV-1 and are characterized by several single amino acid substitutions. The extended spectrum of substrate specificity for CTX-M beta-lactamases is also associated with the emergence of single mutations in the coding genes. The present review describes various molecular-biological methods used to identify determinants of antibiotic resistance. Particular attention is given to the method of hybridization analysis on microarrays, which allows simultaneous multiparametric determination of many genes and point mutations in them. A separate chapter deals with the use of hybridization analysis on microarrays for genotyping of the major clinically significant ESBLs. Specificity of mutation detection by means of hybridization analysis with different detection techniques is compared

Seasonal variation in the diet and the morphometric parameters of the genus Pseudophoxinus sp. (Cyprinidae) in Eastern Algeria

The diet and the morphometric parameters of the Pseudophoxinus sp. (Cyprinidae) in the El Mellah ravine (M’sila, Algeria) were studied by determining body measurements and analyzing the contents of digestive tracts of 320 fish from December 2018 to November 2019. The obtained results show marked diversity within the fish species diets, which can be grouped into three main fractions: (i) a plant fraction; (ii) an animal fraction composed mainly of invertebrate prey; and (iii) fraction consisting of fish eggs (digested by males during the breeding season). The plant fraction was present in all the analyzed digestive tracts, mainly being composed of phytoplankton (algae), namely, Spirogyra sp., Melosira sp. and Navicula sp. with the total relative abundances of 38.7%, 34.4% and 4.1%, respectively. On the other hand, the animal fraction was represented by the Chironomus sp., Austrosimulium sp., and Ecdyonurus sp. dipterans with a total relative abundance of 7.3%, 6.7% and 5.9%, respectively. Pseudophoxinus sp. eggs can also be considered as part of this fraction with the total relative abundance of 2.9%. The age of the fish seems to have an influence on their feeding behaviour. The juveniles of Pseudophoxinus sp. in the study area had a purely phytophagous diet, while adults showed a phytophagous behaviour with an omnivorous tendency. The present study shows that not only the age of the fish but also the seasonal changes (climatic conditions and entry into the breeding season) may have a significant influence on the diet and morphometric parameters of Pseudophoxinus sp. in El Mellah ravine

Calibration and sensitivity of the Virgo detector during its second science run

The Virgo detector is a kilometer-length interferometer for gravitational wave detection located near Pisa (Italy). During its second science run (VSR2) in 2009, six months of data were accumulated with a sensitivity close to its design. In this paper, the methods used to determine the parameters for sensitivity estimation and gravitational wave reconstruction are described. The main quantities to be calibrated are the frequency response of the mirror actuation and the sensing of the output power. Focus is also put on their absolute timing. The monitoring of the calibration data as well as the parameter estimation with independent techniques are discussed to provide an estimation of the calibration uncertainties. Finally, the estimation of the Virgo sensitivity in the frequency-domain is described and typical sensitivities measured during VSR2 are shown.Comment: 30 pages, 23 figures, 1 table. Published in Classical and Quantum Gravity (CQG), Corrigendum include

Targeting Class A and C Serine \u3b2-Lactamases with a Broad-Spectrum Boronic Acid Derivative

Production of \u3b2-lactamases (BLs) is the most widespread resistance mechanism adopted by bacteria to fight \u3b2-lactam antibiotics. The substrate spectrum of BLs has become increasingly broad, posing a serious health problem. Thus, there is an urgent need for novel BL inhibitors. Boronic acid transition-state analogues are able to reverse the resistance conferred by class A and C BLs. We describe a boronic acid analogue possessing interesting and potent broad-spectrum activity vs class A and C serine-based BLs. Starting from benzo(b)thiophene-2-boronic acid (BZBTH2B), a nanomolar non-\u3b2-lactam inhibitor of AmpC that can potentiate the activity of a third-generation cephalosporin against AmpC-producing resistant bacteria, we designed a novel broad-spectrum nanomolar inhibitor of class A and C BLs. Structure-based drug design (SBDD), synthesis, enzymology data, and X-ray crystallography results are discussed. We clarified the inhibitor binding geometry responsible for broad-spectrum activity vs serine-active BLs using double mutant thermodynamic cycle studies

First Low-Latency LIGO+Virgo Search for Binary Inspirals and their Electromagnetic Counterparts

Aims. The detection and measurement of gravitational-waves from coalescing neutron-star binary systems is an important science goal for ground-based gravitational-wave detectors. In addition to emitting gravitational-waves at frequencies that span the most sensitive bands of the LIGO and Virgo detectors, these sources are also amongst the most likely to produce an electromagnetic counterpart to the gravitational-wave emission. A joint detection of the gravitational-wave and electromagnetic signals would provide a powerful new probe for astronomy. Methods. During the period between September 19 and October 20, 2010, the first low-latency search for gravitational-waves from binary inspirals in LIGO and Virgo data was conducted. The resulting triggers were sent to electromagnetic observatories for followup. We describe the generation and processing of the low-latency gravitational-wave triggers. The results of the electromagnetic image analysis will be described elsewhere. Results. Over the course of the science run, three gravitational-wave triggers passed all of the low-latency selection cuts. Of these, one was followed up by several of our observational partners. Analysis of the gravitational-wave data leads to an estimated false alarm rate of once every 6.4 days, falling far short of the requirement for a detection based solely on gravitational-wave data.Comment: 13 pages, 13 figures. For a repository of data used in the publication, go to: http://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=P1100065 Also see the announcement for this paper on ligo.org at: http://www.ligo.org/science/Publication-S6CBCLowLatency

Volatile oils of Thymus serpyllum and Artemisia absinthium: GS-MS analysis and insecticidal activity against Culiseta longiareolata

Culiseta longiareolata (Macquart, 1838) (Diptera, Culicidae) is one of the important mosquito species distributed in Algeria. It acts as a vector of avian malaria, tularemia, Malta fever (brucellosis), and several arboviruses, such as West Nile fever and western encephalitis virus. To eliminate undesirable insect vectors of pathogens, botanical-based insecticides are increasingly recommended. This research was focused on the analysis of the chemical composition of essential oils from Artemisia absinthium (Asteraceae) and Thymus serpyllum (Lamiaceae) obtained by hydrodistillation using gas chromatography – mass spectroscopy (GC-MS). Furthermore, these oils were tested for the first time for their larvicidal activity against fourth-instar larvae of C. longiareolata. In the Th. serpyllum essential oil, linalool (25.40%) was the major constituent, followed by camphor (19.75%) and α-pinene (11.25%). In the A. absinthium essential oil, the major compound was camphor (39.01%), followed by chamazulene (14.51%). Our study found significant larvicidal effects against the fourth-instar larvae, with a direct correlation among the larval mortality rate, applied concentrations, and duration of exposure to the treatment, where the mortality increased over time. Also, the results indicated a significant difference in the mortality rate between the two samples of essential oils. The essential oil extracted from A. absinthium was highly effective against mosquito larvae, achieving the LC50 values of 10.42, 6.19 and 3.82 ppm at 24, 48, and 72 h, respectively, while the essential oil from Th. serpyllum achieved the LC50 values of 12.16, 7.79, and 6.88 ppm. Based on the current results, both the plants could be used as new alternatives for mosquito control

First measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary–Black-hole Merger GW170814

International audienceWe present a multi-messenger measurement of the Hubble constant H 0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, provided that a galaxy catalog of adequate depth and redshift completion is available. Here we present the first Hubble parameter measurement using a black hole merger. Our analysis results in , which is consistent with both SN Ia and cosmic microwave background measurements of the Hubble constant. The quoted 68% credible region comprises 60% of the uniform prior range [20, 140] km s−1 Mpc−1, and it depends on the assumed prior range. If we take a broader prior of [10, 220] km s−1 Mpc−1, we find (57% of the prior range). Although a weak constraint on the Hubble constant from a single event is expected using the dark siren method, a multifold increase in the LVC event rate is anticipated in the coming years and combinations of many sirens will lead to improved constraints on H 0