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

Presupposti giuridici e riflessi medico-legali della vigente legislazione antidoping.

Il doping, inteso come assunzione di sostanze illecite in grado di migliorare il benessere psicofisico e ottimizzare le prestazioni atletiche, è oggi un problema di salute pubblica. Il ricorso a mezzi artificiosi per alterare il risultato delle competizioni può generare gravi danni alla salute e corrompere la lealtà del gesto atletico, costituendo altresì un illecito sportivo e un reato penale, come sancito dalla legislazione italiana corrente. Quest’articolo si propone di analizzare in termini medico-legali la vigente legislazione nazionale in materia, offrendo interpretazioni e riflessioni, e valutando i potenziali riflessi giurisprudenziali che possono scaturire dall’applicazione della legge

The Response of Halophyte (Tetragonia tetragonioides (Pallas) Kuntz.) and Glycophyte (Lactuca sativa L.) Crops to Diluted Seawater and NaCl Solutions: A Comparison between Two Salinity Stress Types

The use of seawater in horticulture is underestimated. Although pure seawater is harmful to most living plants, diluted seawater could represent a promising integration to meet the crop’s nutrient and water requirements. In the current trial, we compared the effects of moderate and high concentrations of seawater and a comparable NaCl solution on a salt-tolerant (Tetragonia tetragonioides) and a salt-sensitive (Lactuca sativa) crop grown in hydroponics. We tested the hypothesis that, due to its mineral composition, diluted seawater would result in a less stressful growing medium than NaCl. We observed that diluted seawater resulted in a less detrimental growing medium compared to an EC-comparable NaCl solution, with remarkable differences between the salt-tolerant and the salt-sensitive species. While the growth rates in Tetragonia did not vary between the two types of stress, diluted seawater led to a higher FW and DW biomass yield in the salt-sensitive lettuce compared to the NaCl treatment. Moreover, NaCl reduced the water consumption and water productivity in Tetragonia. In lettuce, NaCl-treated plants demonstrated lower water use efficiency and water productivity compared to the EC-comparable seawater treatment. Physiological parameters and the concentration of mineral elements, phenolics and proline also demonstrated that, due to different mineral composition, seawater is a less stressful growing medium compared to a NaCl solution at comparable EC

Salinity stress constrains photosynthesis in Fraxinus ornus more when growing in partial shading than in full sunlight: consequences for the antioxidant defence system

BACKGROUND AND AIMS: A major challenge in plant ecophysiology is understanding the effects of multiple sub-optimal environmental conditions on plant performance. In most Mediterranean areas soil salinity builds up during the summer because of low availability of soil water coupled with hot temperatures. Although sunlight and soil salinity may strongly interact in determining a plant's performance, this has received relatively little attention. METHODS: Two-year-old seedlings of Fraxinus ornus were grown outdoors in pots during a Mediterranean summer in either 45 % (shaded plants) or 100 % (sun plants) sunlight irradiance and were supplied with either deionized water or deionized water plus 75 mm NaCl. Morpho-anatomical traits, water and ionic relations, gas exchange and photosystem II performance, concentrations of individual carotenoids, activity of antioxidant enzymes, concentrations of ascorbic acid and individual polyphenols were measured in leaves. Leaf oxidative stress and damage were estimated by in vivo analysis of stable free radicals and ultrastructural analyses. KEY RESULTS: Leaf concentrations of potentially toxic ions did not markedly differ in shaded or sun plants in response to salinity. Leaves of sun plants displayed superior water use efficiency compared with leaves of shaded plants, irrespective of salinity treatment, and had both better stomatal control and higher CO2 carboxylation efficiency than leaves of shaded plants. In the salt-treated groups, the adverse effects of excess midday irradiance were greater in shade than in sun plants. The activity of enzymes responsible for detoxifying hydrogen peroxide decreased in shaded plants and increased in sun plants as a result of salinity stress. In contrast, the activity of guaiacol peroxidase and the concentration of phenylpropanoids increased steeply in response to salinity in shaded plants but were unaffected in sun plants. CONCLUSIONS: It is concluded that salinity may constrain the performance of plants growing under partial shading more severely than that of plants growing under full sun during summer. The results suggest co-ordination within the antioxidant defence network aimed at detoxifying salt-induced generation of reactive oxygen species

Hydrothermal genesis and growth of the banded agates from the Allumiere-Tolfa volcanic district (Latium, Italy)

International audienceIn this work, we studied the hydrothermal agates from the Neogene-Quaternary volcanic district of Allumiere-Tolfa, north-west of Rome (Latium, Italy) using a combination of micro-textural, spectroscopic, and geochemical data. The examined sample consists of (1) an outer cristobalite layer deposited during the early stages of growth, (2) a sequence of chalcedonic bands (including i.e., length-fast, zebraic, and minor length-slow chalcedony) with variable moganite content (up to ca. 48 wt%), (3) an inner layer of terminated hyaline quartz crystals. The textures of the various SiO2 phases and their trace element content (Al, Li, B, Ti, Ga, Ge, As), as well as the presence of mineral inclusions (i.e., Fe-oxides and sulfates), is the result of physicochemical fluctuations of SiO2-bearing fluids. Positive correlation between Al and Li, low Al/Li ratio, and low Ti in hyaline quartz points to low-temperature hydrothermal environment. Local enrichment of B and As in chalcedony-rich layers are attributed to pH fluctuations. Analysis of the FT-IR spectra in the principal OH-stretching region (2750-3750 cm−1) shows that the silanol and molecular water signals are directly proportional. Strikingly, combined Raman and FT-IR spectroscopy on the chalcedonic bands reveals an anticorrelation between the moganite content and total water (SiOH + molH2O) signal. The moganite content is compatible with magmatic-hydrothermal sulfate/alkaline fluids at a temperature of 100-200 °C, whereas the boron-rich chalcedony can be favored by neutral/acidic conditions. The final Bambauer quartz growth lamellae testifies diluted SiO2-bearing solutions at lower temperature. These findings suggest a genetic scenario dominated by pH fluctuations in the circulating hydrothermal fluid

Antioxidant Defences and Oxidative Damage in Salt-treated Olive Plants under Contrasting Sunlight Irradiance

The interactive effects of root-zone salinity and sunlight on leaf biochemistry, with special emphasis on antioxidant defences, were analysed in Olea europaea L. cv. Allora, during the summer period. Plants were grown outside under 15% (shade plants) or 100% sunlight (sun plants) and supplied with 0 or 125 mM NaCl. The following measurements were performed: (1) the contribution of ions and soluble carbohydrates to osmotic potentials; (2) the photosystem II (PSII) photochemistry and the photosynthetic pigment concentration; (3) the concentration and the tissue-specific distribution of leaf flavonoids; (4) the activity of antioxidant enzymes; and (5) the leaf oxidative damage. The concentrations of Na+ and Cl- were significantly greater in sun than in shade leaves, as also observed for the concentration of the ‘antioxidant’ sugar–alcohol mannitol. The de-epoxidation state of violaxanthin-cycle pigments increased in response to salinity stress in sun leaves. This finding agrees with a greater maximal PSII photochemistry (Fv/Fm) at midday, detected in salt-treated than in control plants, growing in full sunshine. By contrast, salt-treated plants in the shade suffered from midday depression in Fv/Fm to a greater degree than that observed in control plants. The high concentration of violaxanthin-cycle pigments in sun leaves suggests that zeaxanthin may protect the chloroplast from photo-oxidative damage, rather than dissipating excess excitation energy via non-photochemical quenching mechanisms. epidermal cells, in response to high sunlight. The activity of antioxidant enzymes varied little because of sunlight irradiance, but declined sharply in response to high salinity in shade leaves. Interestingly, control and particularly salt-treated plants in the shade underwent greater oxidative damage than their sunny counterparts. These findings, which conform to the evolution of O. europaea in sunny environments, suggest that under partial shading, the antioxidant defence system may be ineffective to counter salt-induced oxidative damage Dihydroxy B-ring-substituted flavonoid glycosides accumulate greatly in the mesophyll, not only in the epidermal cells, in response to high sunlight. The activity of antioxidant enzymes varied little because of sunlight irradiance, but declined sharply in response to high salinity in shade leaves. Interestingly, control and particularly salt-treated plants in the shade underwent greater oxidative damage than their sunny counterparts. These findings, which conform to the evolution of O. europaea in sunny environments, suggest that under partial shading, the antioxidant defence system may be ineffective to counter salt-induced oxidative damage