Detection of pulsations and a spectral feature in the X-ray emission of the isolated neutron star 1RXS J214303.7+065419/RBS 1774

We report on the results of a deep XMM-Newton observation of RBS 1774, the most recent dim isolated neutron star candidate found in the ROSAT archive data. Spectral and timing analysis of the high-quality PN and MOS data confirm the association of this source with an isolated neutron star. The spectrum is thermal and blackbody-like, and there is evidence at a significance level > 4sigma that the source is an X-ray pulsar, with spin period of 9.437 s. Spectral fitting reveils the presence of an absorption feature at ~0.7 keV, but at this level data do not have enough resolution to allow us to discriminate between an absorption line or an edge. We compare the newly measured properties of RBS 1774 with those of other known dim isolated neutron stars, and discuss possible interpretations for the absorption feature.Comment: 21 pages, 5 figures, ApJ accepte

Distribution of amiodarone and desethylamiodarone in a patient with acute myocardial infarction after intravenous administration

The autopsy tissues concentration of amiodarone and desethylamiodarone of a man with acute myocardial infarction treated acutely with intravenous amiodarone is reported. Our data indicate that amiodarone is quickly distributed into all highly perfused tissues after intravenous administration with a high amiodarone/desethylamiodarone ratio. We also report here the autopsy case of a woman who died after 30 days of oral therapy with amiodarone. The increase in heart/plasma ratio of amiodarone and desethylamiodarone concentrations and the decrease in amiodarone/desethylamiodarone ratio after one month of therapy could explain the latency in the antiarrhythmic action of the drug

Radiative acceleration and transient, radiation-induced electric fields

The radiative acceleration of particles and the electrostatic potential fields that arise in low density plasmas hit by radiation produced by a transient, compact source are investigated. We calculate the dynamical evolution and asymptotic energy of the charged particles accelerated by the photons and the radiation-induced electric double layer in the full relativistic, Klein-Nishina regime. For fluxes in excess of $10^{27}$ ${\rm erg} {\rm cm}^{-2} {\rm s}^{-1}$, the radiative force on a diluted plasma (n\la 10^{11} cm$^{-3}$) is so strong that electrons are accelerated rapidly to relativistic speeds while ions lag behind owing to their larger inertia. The ions are later effectively accelerated by the strong radiation-induced double layer electric field up to Lorentz factors $\approx 100$, attainable in the case of negligible Compton drag. The asymptotic energies achieved by both ions and electrons are larger by a factor 2--4 with respect to what one could naively expect assuming that the electron-ion assembly is a rigidly coupled system. The regime we investigate may be relevant within the framework of giant flares from soft gamma-repeaters.Comment: 14 pages, 7 figures, ApJ, in press (tentatively scheduled for the v. 592, 2003 issue

Study on the differences of BMI between olms found in cave and the ones sampled in spring

The olm (Proteus anguinus) is a blind amphibian, depigmented and with an extremely reduced metabolism. These are adaptations to cave life that allow the animals to exploit this hostile (from a human perspective) habitat. Adaptations to cave life, should prevent successful exploitation of the external environment. However, although the Proteus is a cave animal, it has been reported by some authors in the spring environment, Our previous results showed that this presence, would seem not to be random, in but linked to very specific factors such as hydroperiod the absence of potential predators. In the light of these results, we have conducted a study with the aim of verifying whether the Proteus benefits from exploiting the trophic resources occurring in springs. Since June 2020 we have sampled 64 springs and 12 caves in the Monfalcone province, each olm found during the sampling was photographed, measured and weighed. A total of 73 different olms were analyzed and the Body Mass Index (BMI) was calculated for each individual. Olms found in springs had a significantly higher BMI than those found in caves. The BMI of springs’ olms was significantly related to amount of the trophic available, evidencing that they took advantages from exploiting the external environment. These results contribute to support the hypothesis of the non-random presence of the Proteus in the spring environment, the olm, in fact, seem to benefit from this type of habitat taking advantage of the greater number of resources present in it

Activity of the olm (Proteus anguinus) in surface habitats: ecological and evolutionary insights

The olm is considered as a classic example of troglobiont organism. However, in the past different observations of individuals of the typical troglomorphic populations have been reported for springs of Venetia Giulia. The aim of this work is to point out the non-random active use of surface habitats by the olm, providing a comparison with the occurrence observed in caves and performing an assessment of factors favouring ecotone habitats exploitation. Since 2020 we started multiple day and night surveys of olms in both springs and caves. Each spring and cave habitat monitored has been characterised by respect to abiotic and biotic features, including planktonic and benthic prey availability. We detected the olm at least once in 10 springs, with a maximum of 9 individuals occurring together. Detection probability in springs and caves was similar. Spring habitats provided higher density of potential prey available. Olms seems to prefer springs without predator fish and temporary hydroperiod. We recorded in one spring a larva of 3.5 cm which could be the smallest ever recorded in the field. We suggest that epigean habitats and borders with surface may have an underestimated importance for animals adapted to subterranean environments, including the olm. Our results stimulate for testing if exploitation of ecotones between surface and groundwater can lead to differentiation in populations/subpopulations of stygobiont animals

Probing stellar winds and accretion physics in high-mass X-ray binaries and ultra-luminous X-ray sources with LOFT

This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of high-mass X-ray binaries and ultra-luminous X-ray sources. For a summary, we refer to the paper.Comment: White Paper in Support of the Mission Concept of the Large Observatory for X-ray Timing. (v2 few typos corrected

Varicocele and adolescents: semen quality after 2 different laparoscopic procedures

The Author analyze their results in adolescent patients treated for idiophatic varicocel