6,923 research outputs found

    Letter from Madeline C. McNamara, United States Department of State, to Geraldine Ferraro

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    Letter from Madeline C. McNamara to Geraldine Ferraro, on behalf on the Italian Desk at the Office of Western European Affairs of the United States Department of State. Letter has handwritten notes.https://ir.lawnet.fordham.edu/vice_presidential_campaign_correspondence_1984_international/1366/thumbnail.jp

    Female vs Males inmates: Authors' reply and sample size calculation

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    Bruno and colleagues highlighted the relatively low absolute-percentage of psychiatric morbidity that we found in our sample, as compared to their male sample. They invited to the use of diagnostic tools, specific for personality disorders and suicidal risk factors, to better investigate these critical issues. In summary, our results showed high percentages of psychiatric morbidity (44%), especially anxiety and depression. Female inmates declared to be most stressed by the distance from family and loved ones, and they did not present any antisocial personality diagnosis. They also showed a resilient reaction to their situation, because more than a half of women requested a supportive psychological therapy during their detention (14/25= 56%), and 10 of them were those with a psychiatric disorder (10/11= 90.9%), thus a higher proportion than those reported in male detainees at the Messina jail (56%), by Zoccali and colleagues (Zoccali et al., 2008). As we have acknowledged, we could further explore other personality disorders and not merely the antisocial personality pathological traits, as we did in our study. In conclusion, we agree with them about the need to repeat the screening for mental health and a deeper ascertainment of specific suicidal risk factors, with an adequate sample. Nonetheless, we believe that our data were not biased, and likely represented the psychological asset of the ladies’ detainee with a final sentence at the Pagliarelli jail of Palermo

    The optical companion to the binary millisecond pulsar J1824-2452H in the globular cluster M28

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    We report on the optical identification of the companion star to the eclipsing millisecond pulsar PSR J1824-2452H in the galactic globular cluster M28 (NGC 6626). This star is at only 0.2" from the nominal position of the pulsar and it shows optical variability (~ 0.25 mag) that nicely correlates with the pulsar orbital period. It is located on the blue side of the cluster main sequence, ~1.5 mag fainter than the turn-off point. The observed light curve shows two distinct and asymmetric minima, suggesting that the companion star is suffering tidal distortion from the pulsar. This discovery increases the number of non-degenerate MSP companions optically identified so far in globular clusters (4 out of 7), suggesting that these systems could be a common outcome of the pulsar recycling process, at least in dense environments where they can be originated by exchange interactions.Comment: accepted for publication on ApJ, 17 pages, 5 figure

    Selective cloning of Gaussian states by linear optics

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    We investigate the performances of a selective cloning machine based on linear optical elements and Gaussian measurements, which allows to clone at will one of the two incoming input states. This machine is a complete generalization of a 1 to 2 cloning scheme demonstrated by U. L. Andersen et al. [Phys. Rev. Lett. vol. 94, 240503 (2005)]. The input-output fidelity is studied for generic Gaussian input state and the effect of non-unit quantum efficiency is also taken into account. We show that if the states to be cloned are squeezed states with known squeezing parameter, then the fidelity can be enhanced using a third suitable squeezed state during the final stage of the cloning process. A binary communication protocol based on the selective cloning machne is also discussed.Comment: 6 pages, 6 figure

    Infrared observations of the candidate double neutron star system PSR J1811-1736

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    PSR J1811-1736 (P=104 ms) is an old (~1.89 Gyrs) binary pulsar (P_orb=18.8 d) in a highly eccentric orbit (e=0.828) with an unidentified companion. Interestingly enough, the pulsar timing solution yields an estimated companion mass 0.93 M_{\odot}<M_C<1.5 M_{\odot}, compatible with that of a neutron star. As such, it is possible that PSR J1811-1736 is a double neutron star (DNS) system, one of the very few discovered so far. This scenario can be investigated through deep optical/infrared (IR) observations. We used J, H, K-band images, obtained as part of the UK Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS), and available in the recent Data Release 9 Plus, to search for its undetected companion of the PSR J1811-1736 binary pulsar. We detected a possible companion star to PSR J1811-1736 within the 3 sigma radio position uncertainty (1.32 arcsec), with magnitudes J=18.61+/-0.07, H=16.65+/-0.03, and K=15.46+/-0.02. The star colours are consistent with either a main sequence (MS) star close to the turn-off or a lower red giant branch (RGB) star, at a pulsar distance of ~5.5 kpc and with a reddening of E(B-V)~4.9. The star mass and radius would be compatible with the constraints on the masses and orbital inclination of the binary system inferred from the mass function and the lack of radio eclipses near superior conjunction. Thus, it is possible that it is the companion to PSR J1811-1736. However, based on the star density in the field, we estimated a quite large chance coincidence probability of ~0.27 between the pulsar and the star, which makes the association unlikely. No other star is detected within the 3 sigma pulsar radio position down to J~20.5, H~19.4$ and K~18.6, which would allow us to rule out a MS companion star earlier than a mid-to-late M spectral type.Comment: 10 pages, 6 figures, accepted for publication on Monthly Notices of the Royal Astronomical Societ

    Electronic Hong-Ou-Mandel interferometry in two-dimensional topological insulators

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    The edge states of a two-dimensional topological insulator are characterized by their helicity, a very remarkable property which is related to the time-reversal symmetry and the topology of the underlying system. We theoretically investigate a Hong-Ou-Mandel like setup as a tool to probe it. Collisions of two electrons with the same spin show a Pauli dip, analogous to the one obtained in the integer quantum Hall case. Moreover, the collisions between electrons of opposite spin also lead to a dip, known as Z2\mathbb{Z}_{2} dip, which is a direct consequence of the constraints imposed by time-reversal symmetry. In contrast to the integer quantum Hall case, the visibility of these dips is reduced by the presence of the additional edge channels, and crucially depends on the properties of the quantum point contact. As a unique feature of this system, we show the possibility of three-electron interference, which leads to a total suppression of the noise independently of the point contact configuration. This is assured by the peculiar interplay between Fermi statistics and topology. This work intends to extend the domain of applicability of electron quantum optics.Comment: 12 pages, 7 figure

    Constraining the true nature of an exotic binary in the core of NGC 6624

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    We report on the identification of the optical counterpart to Star1, the exotic object serendipitously discovered by Deutsch et al. in the core of the Galactic globular cluster NGC 6624. Star1 has been classified by Deutsch et al. as either a quiescent Cataclysmic Variable or a low-mass X-ray binary. Deutsch et al. proposed StarA as possible optical counterpart to this object. We used high-resolution images obtained with the Hubble Space Telescope to perform a variability analysis of the stars close to the nominal position of Star1. While no variability was detected for StarA, we found another star, here named COM_Star1, showing a clear sinusoidal light modulation with amplitude \Delta m_F435W~0.7 mag and orbital period of P_orb~98 min. The shape of the light curve is likely caused by strong irradiation by the primary heating one hemisphere of the companion, thus suggesting a quite hot primary.Comment: Accepted for publication by ApJ Letters; 6 pages, 5 figure

    The giant, horizontal and asymptotic branches of galactic globular clusters. I. The catalog, photometric observables and features

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    A catalog including a set of the most recent Color Magnitude Diagrams (CMDs) is presented for a sample of 61 Galactic Globular Clusters (GGCs). We used this data-base to perform an homogeneous systematic analysis of the evolved sequences (namely, Red Giant Branch (RGB), Horizontal Branch (HB) and Asymptotic Giant Branch (AGB)). Based on this analysis, we present: (1) a new procedure to measure the level of the ZAHB (V_ZAHB) and an homogeneous set of distance moduli obtained adopting the HB as standard candle; (2) an independent estimate for RGB metallicity indicators and new calibrations of these parameters in terms of both spectroscopic ([Fe/H]_CG97) and global metallicity ([M/H], including also the alpha-elements enhancement). The set of equations presented can be used to simultaneously derive a photometric estimate of the metal abundance and the reddening from the morphology and the location of the RGB in the (V,B-V)-CMD. (3) the location of the RGB-Bump (in 47 GGCs) and the AGB-Bump (in 9 GGCs). The dependence of these features on the metallicity is discussed. We find that by using the latest theoretical models and the new metallicity scales the earlier discrepancy between theory and observations (~0.4 mag) completely disappears.Comment: 51 pages, 23 figures, AAS Latex, macro rtrpp4.sty included, accepted by A

    Trihalomethane Precursor Reduction Using Magnesium Coagulation

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    This study investigated the effectiveness of the magnesium coagulation process in reduction of trihalomethane (THM) precursors. The water was obtained from Lake Washington, a highly colored potable water supply which is used by the City of Melbourne, Florida. The THM concentrations in the finished water at Melbourne currently exceed the THM standard of 0.1 mg/l. For Lake Washington water, treatment varies according to seasonal changes in water quality. During the dry period, the recycle magnesium does not perform effectively as a coagulant for THM precursor removal. This is because of the high levels of magnesium in the late water at this time. During the wet period, when magnesium concentrations are very low, it is much more effective. Magnesium sulfate was found to be effective in reducing THM precursors for both types of water. There was a direct correlation observed between THMFP, TOC and color observed in treated water samples. The lack of effectiveness in THMFP, TOC and color removals by recycle magnesium was not found to be due to a lack of magnesium precipitation. Variations in rapid and slow mixing times had no effect on THM precursor removal, but did affect settling of the floc. Addition of alum as a polymer at high pH values was also very effective in reducing the THMFP, TOC and color, and increasing floc sedimentation

    The optical counterpart to the X-ray transient IGR J18245-2452 in the globular cluster M28

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    We report on the identification of the optical counterpart to the recently detected INTEGRAL transient IGR J18245-2452 in the Galactic globular cluster M28. From the analysis of a multi epoch HST dataset we have identified a strongly variable star positionally coincident with the radio and Chandra X-ray sources associated to the INTEGRAL transient. The star has been detected during both a quiescent and an outburst state. In the former case it appears as a faint, unperturbed main sequence star, while in the latter state it is about two magnitudes brighter and slightly bluer than main sequence stars. We also detected Halpha excess during the outburst state, suggestive of active accretion processes by the neutron star.Comment: Accepted for publication by ApJ; 15 pages, 4 figures, 1 tabl
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