9,091 research outputs found
Impact of the tidal p-g instability on the gravitational wave signal from coalescing binary neutron stars
Recent studies suggest that coalescing neutron stars are subject to a fluid
instability involving the nonlinear coupling of the tide to -modes and
-modes. Its influence on the inspiral dynamics and thus the gravitational
wave signal is, however, uncertain because we do not know precisely how the
instability saturates. Here we construct a simple, physically motivated model
of the saturation that allows us to explore the instability's impact as a
function of the model parameters. We find that for plausible assumptions about
the saturation, current gravitational wave detectors might miss of
events if only point particle waveforms are used. Parameters such as the chirp
mass, component masses, and luminosity distance might also be significantly
biased. On the other hand, we find that relatively simple modifications to the
point particle waveform can alleviate these problems and enhance the science
that emerges from the detection of binary neutron stars.Comment: 15 pages, 12 figures, 1 tabl
Mesothelioma and thymic tumors: Treatment challenges in (outside) a network setting
The management of patients with mesothelioma and thymic malignancy requires continuous multidisciplinary expertise at any step of the disease. A dramatic improvement in our knowledge has occurred in the last few years, through the development of databases, translational research programs, and clinical trials. Access to innovative strategies represents a major challenge, as there is a lack of funding for clinical research in rare cancers and their rarity precludes the design of robust clinical trials that could lead to specific approval of drugs. In this context, patient-centered initiatives, such as the establishment of dedicated networks, are warranted. International societies, such as IMIG (International Mesothelioma Interest Group) and ITMIG (International Thymic Malignancy Interest Group) provide infrastructure for global collaboration, and there are many advantages to having strong regional groups working on the same issues. There may be regional differences in risk factors, susceptibility, management and outcomes. The ability to address questions both regionally as well as globally is ideal to develop a full understanding of mesothelioma and thymic malignancies. In Europe, through the integration of national networks with EURACAN, the collaboration with academic societies and international groups, the development of networks in thoracic oncology provides multiplex integration of clinical care and research, ultimately ensuring equal access to high quality care to all patients, with the opportunity of conducting high level clinical and translational research projects
On The Origin Of The Gamma Rays From The Galactic Center
The region surrounding the center of the Milky Way is both astrophysically
rich and complex, and is predicted to contain very high densities of dark
matter. Utilizing three years of data from the Fermi Gamma Ray Space Telescope
(and the recently available Pass 7 ultraclean event class), we study the
morphology and spectrum of the gamma ray emission from this region and find
evidence of a spatially extended component which peaks at energies between 300
MeV and 10 GeV. We compare our results to those reported by other groups and
find good agreement. The extended emission could potentially originate from
either the annihilations of dark matter particles in the inner galaxy, or from
the collisions of high energy protons that are accelerated by the Milky Way's
supermassive black hole with gas. If interpreted as dark matter annihilation
products, the emission spectrum favors dark matter particles with a mass in the
range of 7-12 GeV (if annihilating dominantly to leptons) or 25-45 GeV (if
annihilating dominantly to hadronic final states). The intensity of the
emission corresponds to a dark matter annihilation cross section consistent
with that required to generate the observed cosmological abundance in the early
universe (sigma v ~ 3 x 10^-26 cm^3/s). We also present conservative limits on
the dark matter annihilation cross section which are at least as stringent as
those derived from other observations.Comment: 13 pages, 11 figure
High-Tip-Speed, Low-Loading Transonic Fan Stage. Part 1: Aerodynamic and Mechanical Design
A high-tip-speed, low-loading transonic fan stage was designed to deliver an overall pressure ratio of 1.5 with an adiabatic efficiency of 86 percent. The design flow per unit annulus area is 42.0 pounds per square foot. The fan features a hub/tip ratio of 0.46, a tip diameter of 28.74 in. and operates at a design tip speed of 1600 fps. For these design conditions, the rotor blade tip region operates with supersonic inlet and supersonic discharge relative velocities. A sophisticated quasi-three-dimensional characteristic section design procedure was used for the all-supersonic sections and the inlet of the midspan transonic sections. For regions where the relative outlet velocities are supersonic, the blade operates with weak oblique shocks only
The importance of considering fibular robusticity when inferring the mobility patterns of past populations
In this chapter we investigate the lower limb structural rigidity (using cross-sectional geometric properties of the diaphyseal midshaft) within a sample of 124 individuals from the Late Upper Paleolithic, Neolithic and Iron Age from Italy, Medieval Germany, and twenty-first Century Britain (long distance runners, field hockey players, and sedentary controls). Late Upper Paleolithic, Neolithic and Iron Age samples were settled in rugged areas, whereas the other samples inhabited plain areas. The aim of this study is to assess whether fibular diaphyseal properties reflect mobility patterns or terrain properties in past populations. Both fibular rigidity and relative fibular rigidity ratio (fibula/tibia) have been analyzed. Results reveal that Late Upper Paleolithic, Neolithic and Iron Age samples show high fibular rigidity and have values of relative fibular rigidity that are most similar to modern hockey players. The relative fibular diaphyseal rigidity of hockey players has been previously explained as the consequence of their dynamic and repetitive change of direction. Late Upper Paleolithic and Neolithic individuals are thought to have been highly terrestrially mobile, while Iron Age people were probably fairly sedentary. However, all of the three groups lived in areas of uneven terrain. We conclude that fibular rigidity and relative fibular rigidity are influenced by factors that increase foot eversion/inversion such as frequent directional changes and uneven terrain. The results of this study suggest that inclusion of the fibula provides a valuable additional perspective that complements traditional predictions of mobility patterns based on the femur or the tibia alone
Resistance traits and AFLP characterization of diploid primitive tuber-bearing potatoes.
ISSN: 0925-986
The Estimation of the Effective Centre of Mass Energy in q-qbar-gamma Events from DELPHI
The photon radiation in the initial state lowers the energy available for the
ee collisions; this effect is particularly important at LEP2 energies
(above the mass of the Z boson). Being aligned to the beam direction, such
initial state radiation is mostly undetected. This article describes the
procedure used by the DELPHI experiment at LEP to estimate the effective
centre-of-mass energy in hadronic events collected at energies above the Z
peak. Typical resolutions ranging from 2 to 3 GeV on the effective
center-of-mass energy are achieved, depending on the event topology.Comment: 12 pages, 6 figure
Strontium Functionalization of Biomaterials for Bone Tissue Engineering Purposes: A Biological Point of View
Strontium (Sr) is a trace element taken with nutrition and found in bone in close connection to native hydroxyapatite. Sr is involved in a dual mechanism of coupling the stimulation of bone formation with the inhibition of bone resorption, as reported in the literature. Interest in studying Sr has increased in the last decades due to the development of strontium ranelate (SrRan), an orally active agent acting as an anti-osteoporosis drug. However, the use of SrRan was subjected to some limitations starting from 2014 due to its negative side effects on the cardiac safety of patients. In this scenario, an interesting perspective for the administration of Sr is the introduction of Sr ions in biomaterials for bone tissue engineering (BTE) applications. This strategy has attracted attention thanks to its positive effects on bone formation, alongside the reduction of osteoclast activity, proven by in vitro and in vivo studies. The purpose of this review is to go through the classes of biomaterials most commonly used in BTE and functionalized with Sr, i.e., calcium phosphate ceramics, bioactive glasses, metal-based materials, and polymers. The works discussed in this review were selected as representative for each type of the above-mentioned categories, and the biological evaluation in vitro and/or in vivo was the main criterion for selection. The encouraging results collected from the in vitro and in vivo biological evaluations are outlined to highlight the potential applications of materials’ functionalization with Sr as an osteopromoting dopant in BTE
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