A New Digital Preoperative Planning Method for Total Hip Arthroplasties

Preoperative templating is an important part of a THA. The ability to accurately determine magnification of the hip on the radiograph and apply identical magnification to the radiograph and template will improve accuracy of preoperative templating of THA. We designed a templating method using a new way of determining the hip magnification with a linear relationship between magnification of the hip and the reference object on top of the pubis symphysis; the relationship was determined on 50 radiographs. We then compared our method with two other templating methods: an analog method assuming an average hip magnification of 15% and a digital method determining the hip magnification with a one-to-one relationship between the reference object and the hip. All methods were reproducible. Uniform undersizing occurred when templating with the digital method based on the one-to-one relationship; the analog method best predicted the implanted prosthesis size, closely followed by our new digital templating method; the new method will be particularly applicable for preoperative THA when analog methods are replaced by digital methods

An enigmatic long-lasting γ-ray burst not accompanied by a bright supernova

Gamma-ray bursts (GRBs) are short, intense flashes of soft γ-rays coming from the distant Universe. Long-duration GRBs (those lasting more than ~2s) are believed to originate from the deaths of massive stars, mainly on the basis of a handful of solid associations between GRBs and supernovae. GRB 060614, one of the closest GRBs discovered, consisted of a 5-s hard spike followed by softer, brighter emission that lasted for ~100s (refs 8, 9). Here we report deep optical observations of GRB 060614 showing no emerging supernova with absolute visual magnitude brighter than MV=-13.7. Any supernova associated with GRB 060614 was therefore at least 100 times fainter, at optical wavelengths, than the other supernovae associated with GRBs. This demonstrates that some long-lasting GRBs can either be associated with a very faint supernova or produced by different phenomena.Fil: Della Valle, M.. Osservatorio Astrofisico di Arcetri; ItaliaFil: Chincarini, G.. Osservatorio Astronomico di Brera; ItaliaFil: Panagia, N.. Space Telescope Science Institute; Estados UnidosFil: Tagliaferri, G.. Osservatorio Astronomico di Brera; ItaliaFil: Malesani, D.. International School for Advanced Studies; ItaliaFil: Testa, V.. Osservatorio Astronomico di Roma; ItaliaFil: Fugazza, D.. Osservatorio Astronomico di Brera; ItaliaFil: Campana, S.. Osservatorio Astronomico di Brera; ItaliaFil: Covino, S.. Osservatorio Astronomico di Brera; ItaliaFil: Mangano, V.. Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo; ItaliaFil: Antonelli, L. A.. Osservatorio Astronomico di Roma; ItaliaFil: D'Avanzo, P.. Osservatorio Astronomico di Brera; ItaliaFil: Hurley, K.. University Of California Berkeley; Estados UnidosFil: Mirabel Miquele, Igor Felix. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Pellizza González, Leonardo Javier. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Piranomonte, S.. Osservatorio Astronomico di Roma; ItaliaFil: Stella, L.. Osservatorio Astronomico di Roma; Itali

The secrets of T Pyxidis II. A recurrent nova that will not become a SN Ia

By various methods, we obtained L$_{disk}$ $\sim$ 70 L$_{\odot}$ and $\dot{M}$ $\sim$1.1 $\times$ 10$^{-8}$ M$_{\odot}$yr$^{-1}$. These values were about twice as high in the pre-1966-outburst epoch. This allowed the first direct estimate of the total mass accreted before outburst, M$_{accr}$=$\dot{M}_{pre-OB}$ $\cdot \Delta$t, and its comparison with the critical ignition mass M$_{ign}$. We found M$_{accr}$ and M$_{ign}$ to be in perfect agreement (with a value close to 5 $\times$ 10$^{-7}$M$_{\odot}$) for M$_1$ $\sim$ 1.37 M$_{\odot}$, which provides a confirmation of the thermonuclear runaway theory. The comparison of the observed parameters of the eruption phase, with the corresponding values in the grid of models by Yaron and collaborators, provides satisfactory agreement for values of M$_1$ close to 1.35 M$_{\odot}$ and log$\dot{M}$ between -8.0 and -7.0, but the observed value of the decay time t$_3$ is higher than expected. The long duration of the optically thick phase during the recorded outbursts of T Pyx, a spectroscopic behavior typical of classical novae, and the persistence of P Cyg profiles, constrains the ejected mass M$_{ign}$ to within 10$^{-5}$ - 10$^{-4}$ M$_{\odot}$. Therefore, T Pyx ejects far more material than it has accreted, and the mass of the white dwarf will not increase to the Chandrasekhar limit as generally believed in recurrent novae. A detailed study based on the UV data excludes the possibility that T Pyx belongs to the class of the supersoft X-ray sources, as has been postulated. XMM-NEWTON observations have revealed a weak, hard source and confirmed this interpretation

BVRI Light Curves for 29 Type Ia Supernovae

BVRI light curves are presented for 27 Type Ia supernovae discovered during the course of the Calan/Tololo Survey and for two other SNe Ia observed during the same period. Estimates of the maximum light magnitudes in the B, V, and I bands and the initial decline rate parameter m15(B) are also given.Comment: 17 pages, figures and tables are not included (contact first author if needed), to appear in the Astronomical Journa

Early-type galaxies with core collapse supernovae

It is widely accepted that the progenitors of core collapse SNe are young massive stars and therefore their host galaxies are mostly spiral or irregular galaxies dominated by a young stellar population. Surprisingly, among morphologically classified hosts of core collapse SNe, we find 22 cases where the host has been classified as an Elliptical or S0 galaxy. To clarify this apparent contradiction, we carry out a detailed morphological study and an extensive literature search for additional information on the sample objects. Our results are as follows: 1. Of 22 "early type" objects, 17 are in fact misclassified spiral galaxies, one is a misclassified irregular, and one is a misclassified ring galaxy. 2. Of the 3 objects maintaining the early type classification, one (NGC2768) is a suspected merger remnant, another (NGC4589) is definitely a merger, and the third (NGC2274) is in close interaction. The presence of some amount of young stellar population in these galaxies is therefore not unexpected. These results confirm the presence of a limited, but significant, number of core collapse SNe in galaxies generally classified of early type. In all cases, anyway, there are independent indicators of the presence in host galaxies of recent star formation due to merging or gravitational interaction.Comment: 12 pages, 1 figure, 1 table, accepted for publication in A&

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum