6,400 research outputs found

    Studies of waveform requirements for intermediate mass-ratio coalescence searches with advanced detectors

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    The coalescence of a stellar-mass compact object into an intermediate-mass black hole (intermediate mass-ratio coalescence; IMRAC) is an important astrophysical source for ground-based gravitational-wave interferometers in the so-called advanced configuration. However, the ability to carry out effective matched-filter based searches for these systems is limited by the lack of reliable waveforms. Here we consider binaries in which the intermediate-mass black hole has mass in the range 24 - 200 solar masses with a stellar-mass companion having masses in the range 1.4 - 18.5 solar masses. In addition, we constrain the mass ratios, q, of the binaries to be in the range 1/140 < q < 1/10 and we restrict our study to the case of circular binaries with non-spinning components. We investigate the relative contribution to the signal-to-noise ratio (SNR) of the three different phases of the coalescence: inspiral, merger and ringdown. We show that merger and ringdown contribute to a substantial fraction of the total SNR over a large portion of the mass parameter space, although in a limited portion the SNR is dominated by the inspiral phase. We further identify three regions in the IMRAC mass-space in which: (i) inspiral-only searches could be performed with losses in detection rates L in the range 10% < L < 27%, (ii) searches based on inspiral-only templates lead to a loss in detection rates in the range 27% < L < 50%$, and (iii) templates that include merger and ringdown are essential to prevent losses in detection rates greater than 50%. We investigate the effectiveness with which the inspiral-only portion of the IMRAC waveform space is covered by comparing several existing waveform families in this regime. Our results reinforce the importance of extensive numerical relativity simulations of IMRACs and the need for further studies of suitable approximation schemes in this mass range.Comment: 10 pages, 3 figure

    Sol–gel synthesis and thermal behavior of bioactive ferrous citrate–silica hybrid materials

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    Imbalance of the iron level in the body causes several diseases. In particular, the low level of iron, during pregnancy, is responsible for the iron deficiency anemia, and even of neurodegenerative diseases. Although the treatment of iron deficiency anemia with oral iron supplements has been known, this problem still afflicts many people. The aim of this work was the development of a system able to release ferrous ions in a controlled manner. Controlled drug release for medical applications, indeed, appears to be a very interesting alternative to a systemic therapy because it is assurance of treatment continuity and drug stability and optimizes drug absorption. For this purpose, ferrous citrate (Fe(II)C) was synthesized by a redox reaction between iron powder and citric acid. Fourier transform infrared spectroscopy (FTIR), 1,10-phenanthroline and sodium thiocyanate colorimetric assays confirmed that only Fe(II)C was obtained by redox reaction. Afterward, obtained Fe(II)C was embedded within a SiO2 matrix in different mass percentage, by means of a sol–gel route. FTIR spectroscopy and simultaneous thermogravimetry/first-order derivative of thermogravimetry were used to confirm the Fe(II)C presence in the silica matrix and to investigate the thermal behavior of the sol–gel materials, respectively. The bioactivity test carried out by soaking the synthesized drug delivery systems in a simulated body fluid showed that the biological properties of the silica matrix are not modified by the presence of Fe(II)C

    Factors affecting use and understanding of nutrition information on food labels: evidences from consumers

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    In the past years, European population has experienced an increase in several chronic diseases linked to dietary and lifestyle factors. In particular obesity is increasing at an alarming rate all over Europe, while warnings about its diffusion have intensified. As a result nutrition-related measures are highly ranked in the agenda of the European Union political priorities. Specifically, at the end of 2011 the EU introduced new rules on food labelling requirements by adding a nutritional declaration. In this context the current paper explores factors affecting use and understanding of nutrition information on food labels in Italy and provides potentially useful assistance for the implementation of new nutrition labelling. Results of a direct survey on a random sample of 400 food shoppers identifies different profiles of consumers, through the use of PCA and Cluster Analysis. Main findings reveal the need to focus primarily on education campaigns and provide specific indications for developers and marketers as well as government bodies that are interested in designing consumer communication strategies and effective health programs

    Factors affecting use and understanding of nutrition information on food labels: evidences from consumers

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    In the past years, European population has experienced an increase in several chronic diseases linked to dietary and lifestyle factors. In particular obesity is increasing at an alarming rate all over Europe, while warnings about its diffusion have intensified. As a result nutrition-related measures are highly ranked in the agenda of the European Union political priorities. Specifically, at the end of 2011 the EU introduced new rules on food labelling requirements by adding a nutritional declaration. In this context the current paper explores factors affecting use and understanding of nutrition information on food labels in Italy and provides potentially useful assistance for the implementation of new nutrition labelling. Results of a direct survey on a random sample of 400 food shoppers identifies different profiles of consumers, through the use of PCA and Cluster Analysis. Main findings reveal the need to focus primarily on education campaigns and provide specific indications for developers and marketers as well as government bodies that are interested in designing consumer communication strategies and effective health programs

    Media use during adolescence: the recommendations of the Italian Pediatric Society.

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    BACKGROUND: The use of media device, such as smartphone and tablet, is currently increasing, especially among the youngest. Adolescents spend more and more time with their smartphones consulting social media, mainly Facebook, Instagram and Twitter because. Adolescents often feel the necessity to use a media device as a means to construct a social identity and express themselves. For some children, smartphone ownership starts even sooner as young as 7 yrs, according to internet safety experts. MATERIAL AND METHODS: We analyzed the evidence on media use and its consequences in adolescence. RESULTS: In literature, smartphones and tablets use may negatively influences the psychophysical development of the adolescent, such as learning, sleep and sigh. Moreover, obesity, distraction, addiction, cyberbullism and Hikikomori phenomena are described in adolescents who use media device too frequently. The Italian Pediatric Society provide action-oriented recommendations for families and clinicians to avoid negative outcomes. CONCLUSIONS: Both parents and clinicians should be aware of the widespread phenomenon of media device use among adolescents and try to avoid psychophysical consequences on the youngest

    Infinite index extensions of local nets and defects

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    Subfactor theory provides a tool to analyze and construct extensions of Quantum Field Theories, once the latter are formulated as local nets of von Neumann algebras. We generalize some of the results of [LR95] to the case of extensions with infinite Jones index. This case naturally arises in physics, the canonical examples are given by global gauge theories with respect to a compact (non-finite) group of internal symmetries. Building on the works of Izumi, Longo, Popa [ILP98] and Fidaleo, Isola [FI99], we consider generalized Q-systems (of intertwiners) for a semidiscrete inclusion of properly infinite von Neumann algebras, which generalize ordinary Q-systems introduced by Longo [Lon94] to the infinite index case. We characterize inclusions which admit generalized Q-systems of intertwiners and define a braided product among the latter, hence we construct examples of QFTs with defects (phase boundaries) of infinite index, extending the family of boundaries in the grasp of [BKLR16].Comment: 50 page

    The information content of gravitational wave harmonics in compact binary inspiral

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    The nonlinear aspect of gravitational wave generation that produces power at harmonics of the orbital frequency, above the fundamental quadrupole frequency, is examined to see what information about the source is contained in these higher harmonics. We use an order (4/2) post-Newtonian expansion of the gravitational wave waveform of a binary system to model the signal seen in a spaceborne gravitational wave detector such as the proposed LISA detector. Covariance studies are then performed to determine the ultimate accuracy to be expected when the parameters of the source are fit to the received signal. We find three areas where the higher harmonics contribute crucial information that breaks degeneracies in the model and allows otherwise badly-correlated parameters to be separated and determined. First, we find that the position of a coalescing massive black hole binary in an ecliptic plane detector, such as OMEGA, is well-determined with the help of these harmonics. Second, we find that the individual masses of the stars in a chirping neutron star binary can be separated because of the mass dependence of the harmonic contributions to the wave. Finally, we note that supermassive black hole binaries, whose frequencies are too low to be seen in the detector sensitivity window for long, may still have their masses, distances, and positions determined since the information content of the higher harmonics compensates for the information lost when the orbit-induced modulation of the signal does not last long enough to be apparent in the data.Comment: 13 pages, 5 figure

    ESA, iron therapy and new drugs: Are there new perspectives in the treatment of anaemia?

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    Anemia is a well-known consequence of chronic kidney disease (CKD); it is mainly due to a relative insufficiency of erythropoietin synthesis by the failing kidneys. Over the years, the combination of erythropoiesis stimulating agents (ESA) and iron has become the standard of care of anemia. All ESAs effectively increase hemoglobin (Hb) levels in a substantial percentage of patients. However, in the last decade, their use has been surrounded by safety issues in increased cardiovascular risk, especially when used at high doses in inflamed and hyporesponsive patients. This has led to the definition of a more cautious Hb target. Iron deficiency is very frequent in CKD patients, with a higher frequency in non-dialysis patients. Traditionally, iron supplementation is mostly used as supportive therapy for anemia control. However, the concept is growing that intravenous iron therapy per se could be beneficial in the presence of heart failure. A new class of drugs, prolyl hydroxylase domain (PHD) inhibitors (PHD inhibitors) is becoming available for the treatment of anemia in CKD patients. Theoretically, these agents have a number of advantages, the main ones being that of stimulating the synthesis of endogenous erythropoietin and increasing iron avail-ability. The impact of their future use in clinical practice is still to be defined. Another possible strategy could be targeting serum hepcidin and its related pathways. This possibility is fascinating from the scientific point of view, but at present its development phase is still far from clinical application

    Retroactivity attenuation in signaling cascades

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    It has been shown in an earlier work that impedance-like effects, called retroactivity, are found at the interconnection of biomolecular systems just as they occur in several engineering systems. These effects are particularly relevant in signaling cascades that have several downstream targets. These cascades have been extensively studied to determine how a stimulus at the top of the cascade is transmitted and amplified as it propagates toward the bottom of the cascade. In principle, because of retroactivity, a perturbation at the bottom of the cascade can propagate upstream. In this paper, we study the extent to which this propagation occurs by analytically finding retroactivity gains at each stage of the cascade. These gains determine whether a perturbation at the bottom of the cascade is amplified or attenuated as it propagates upstream.United States. Air Force Office of Scientific Research (Grant FA9550-09-1-0211

    Searching for Hyperspectral Optical Proxies to Aid Chesapeake Bay Resource Managers in the Detection of Poor Water Quality

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    Shellfish aquaculture is a growing industry in the Chesapeake Bay. As population grows near the coast, extreme weather events cause a greater volume of pollutant runoff from impervious surfaces and agricultural lands. Resource managers who monitor shellfish beds need reliable information on a variety of water quality indicators at higher frequency than is possible through field monitoring programs and at a higher level of detail than current satellite products can provide. Although many factors causing degraded water quality that can impact human health are not currently discernable by traditional multispectral techniques, hyperspectral imagery offers a new opportunity to detect phytoplankton communities associated with harmful algal blooms and biotoxin production. Together with resource managers in their routine monitoring of sites around the bay from small boats, we have been exploring remotely sensed optical proxies for the detection of harmful algal blooms and sewage. Early warning by remote sensing could guide sampling and improve the efficiency of shellfish bed closures, ultimately improving health outcomes for humans and animals. An extensive network of routine sampling by Chesapeake Bay Program managers makes this is an ideal location to develop and test future satellite data products to support management decisions. Next generation hyperspectral measurements from the future Plankton Aerosol Cloud ocean Ecosystem (PACE) mission at nearly daily frequency, combined with the potential of higher spatial resolution from the Surface Biology and Geology (SBG) observing system recommended in the recent Decadal Survey, along with high frequency observations from the newly selected Geostationary Littoral Imaging and Monitoring Radiometer (GLIMR) Earth Venture Instrument make this a critical time for defining the needs of the aquaculture and resource management community to save lives, time, and money
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