952 research outputs found

    Changes in Some Egg Components and Analytical Values Due to Hen Age

    Get PDF
    Abstract The influence of hen age on some egg characteristics was studied. Two commercial breeds of brown hens, namely Warren and Hy-Line, were considered at seven different ages. The variables analyzed were the weights of yolk and thick and thin albumen, pH, and the concentrations of glucose, uridine, and uric and pyroglutamic acids of separated yolk and albumen. Albumen and yolk average weights and the proportion of yolk in the edible part of egg increased with hen age, whereas the average ratio of thick to thin albumen was not influenced by the progress of the laying cycle. Glucose, uridine, and uric acid were also not influenced by hen age. Pyroglutamic acid, which is detectable in yolk and not in the albumen of a fresh egg, showed a characteristic trend in yolk. Its concentration dramatically increased in the middle of the laying cycle and then decreased to values close to those observed in eggs of the young layers

    Photometric and spectroscopic study of the intermediate age open cluster NGC 3960

    Full text link
    We present CCD UBVI photometry and high-resolution spectroscopy of the intermediate age open cluster NGC 3960. The colour - magnitude diagrams (CMDs) derived from the photometric data and interpreted with the synthetic CMD method allow us to estimate the cluster parameters. We derive: age = 0.9 or 0.6 Gyr (depending on whether or not overshooting from convective regions is included in the adopted stellar models), distance (m-M)0 = 11.6 +/- 0.1, reddening E(B-V) = 0.29 +/- 0.02, differential reddening Delta E(B-V) = 0.05 and approximate metallicity between solar and half of solar. We obtained high resolution spectra of three clump stars, and derived an average [Fe/H] = -0.12 (rms 0.04 dex), in very good agreement with the photometric determination. We also obtained abundances of alpha-elements, Fe-peak elements, and of Ba. The reddenings toward individual stars derived from the spectroscopic temperatures and the Alonso et al. calibrations give further support to the existence of significative variations across the cluster.Comment: Accepted for publication on MNRAS; fig. 3, 4, 5, 6 at degraded resolutio

    Tailoring antiplatelet therapy in older patients with coronary artery disease

    Get PDF
    The older population represents a unique subset of patients due to a higher rate of comorbidities and risk factors, which can lead to a higher rate of ischemic and bleeding events. As a result, older adults are mainly underrepresented or excluded from randomized trials. Although the advancement in the percutaneous coronary intervention field with the development of new technologies, techniques, and potent antiplatelet therapy led to a reduction of ischemic risk, there is still a concern regarding bleeding hazards. Apart from the global utilization of less invasive trans-radial approach and proton pump inhibitors to reduce bleeding risk, proper tailoring of antiplatelet therapy in the older person is imperative. So far, several antiplatelet drugs have been introduced in different clinical scenarios, with dual antiplatelet therapy (combination of acetylsalicylic acid and P2Y12 inhibitor) recommended after percutaneous coronary intervention. The decision on the choice of antiplatelet drug and the DAPT duration is challenging and should be based on the relationship between ischemia and bleeding with the purpose of reducing ischemic events but not at the expense of increased bleeding complications. This is particularly important in the older population, where the evidence is obscure. The main objective of this review is to summarize the available evidence on contemporary antiplatelet therapy and different approaches of de-escalation strategies in older patients after percutaneous coronary intervention.What is the context?The older population represents a unique subset of patients due to a higher rate of comorbidities, risk factors, and unfavorable prognostic features, which can lead to a higher rate of ischemic and bleeding events. They are either excluded or underrepresented in most randomized clinical trials, which is why guidelines recommendation should be taken cautiously. Thus, the decision on the choice of antiplatelet therapy and its duration after percutaneous coronary intervention in older adults is challenging and should be tailored to a particular patient to avoid bleeding complications but not at the expense of increased ischemic events.What is new?In this review, we summarize all available evidence on contemporary antiplatelet therapy and different approaches of de-escalation strategies in older patients after percutaneous coronary intervention. In particular, several recommended approaches in patients with high bleeding risk, are thoroughly discussed in this review: De-escalation strategies with discontinuation of one antiplatelet drugDe-escalation strategy with switching between P2Y12 inhibitorsDe-escalation strategy based on dose reductionFinally, based on the current knowledge on factors contributing to high bleeding risk and the aforementioned antiplatelet modification approaches, in this review, we propose antiplatelet algorithm after percutaneous coronary intervention in older adults.What is the impact?The review provides comprehensive knowledge on antiplatelet therapy in older population and may help in tailoring antiplatelet therapy in this unique subset of patients

    The pseudobulge of NGC 1292

    Full text link
    The photometric and kinematic properties of Sb NGC 1292 suggest it hosts a pseudobulge. The properties of the stellar population of such a pseudobulge are consistent with a slow buildup within a scenario of secular evolution.Comment: 2 pages, 1 figure to appear in the proceedings of "Formation and Evolution of Galaxy Disks", Rome, October 2007, Eds. J. Funes and E. M. Corsin

    Magnetic losses in Si-Fe alloys for avionic applications

    Get PDF
    This paper presents an experimental analysis of the rotational power losses of the magnetic materials of transformers, motors and actuators used in avionic environment. A large frequency range is investigated using a suitable experimental test frame developed to measure the power losses for a circular magnetization. The results about different silicon iron alloys with different textures and thickness are considered and compared

    Kinematic and stellar population properties of the counter-rotating components in the S0 galaxy NGC 1366

    Get PDF
    Context. Many disk galaxies host two extended stellar components that rotate in opposite directions. The analysis of the stellar populations of the counter-rotating components provides constraints on the environmental and internal processes that drive their formation. Aims. The S0 NGC 1366 in the Fornax cluster is known to host a stellar component that is kinematically decoupled from the main body of the galaxy. Here we successfully separated the two counter-rotating stellar components to independently measure the kinematics and properties of their stellar populations. Methods. We performed a spectroscopic decomposition of the spectrum obtained along the galaxy major axis and separated the relative contribution of the two counter-rotating stellar components and of the ionized-gas component. We measured the line-strength indices of the two counter-rotating stellar components and modeled each of them with single stellar population models that account for the \u3b1/Fe overabundance. Results. We found that the counter-rotating stellar component is younger, has nearly the same metallicity, and is less \u3b1/Fe enhanced than the corotating component. Unlike most of the counter-rotating galaxies, the ionized gas detected in NGC 1366 is neither associated with the counter-rotating stellar component nor with the main galaxy body. On the contrary, it has a disordered distribution and a disturbed kinematics with multiple velocity components observed along the minor axis of the galaxy. Conclusions. The different properties of the counter-rotating stellar components and the kinematic peculiarities of the ionized gas suggest that NGC 1366 is at an intermediate stage of the acquisition process, building the counter-rotating components with some gas clouds still falling onto the galaxy. \ua9 ESO 2017

    Recovering star formation histories: Integrated-light analyses vs stellar colour-magnitude diagrams

    Full text link
    Accurate star formation histories (SFHs) of galaxies are fundamental for understanding the build-up of their stellar content. However, the most accurate SFHs - those obtained from colour-magnitude diagrams (CMDs) of resolved stars reaching the oldest main sequence turnoffs (oMSTO) - are presently limited to a few systems in the Local Group. It is therefore crucial to determine the reliability and range of applicability of SFHs derived from integrated light spectroscopy, as this affects our understanding of unresolved galaxies from low to high redshift. To evaluate the reliability of current full spectral fitting techniques in deriving SFHs from integrated light spectroscopy by comparing SFHs from integrated spectra to those obtained from deep CMDs of resolved stars. We have obtained a high signal--to--noise (S/N \sim 36.3 per \AA) integrated spectrum of a field in the bar of the Large Magellanic Cloud (LMC) using EFOSC2 at the 3.6 meter telescope at La Silla Observatory. For this same field, resolved stellar data reaching the oMSTO are available. We have compared the star formation rate (SFR) as a function of time and the age-metallicity relation (AMR) obtained from the integrated spectrum using {\tt STECKMAP}, and the CMD using the IAC-star/MinnIAC/IAC-pop set of routines. For the sake of completeness we also use and discuss other synthesis codes ({\tt STARLIGHT} and {\tt ULySS}) to derive the SFR and AMR from the integrated LMC spectrum. We find very good agreement (average differences \sim 4.1 %\%) between the SFR(t) and the AMR obtained using {\tt STECKMAP} on the integrated light spectrum, and the CMD analysis. {\tt STECKMAP} minimizes the impact of the age-metallicity degeneracy and has the advantage of preferring smooth solutions to recover complex SFHs by means of a penalized χ2\chi^2. [abridged]Comment: 23 pages, 24 figures. Accepted for publication in A&A (6 Sep 2015

    Water resource management through systemic approach: The case of Lake Bracciano

    Get PDF
    Today natural water resources are becoming scarce, both due to global climate change but also due to irresponsible behaviour of human beings. Lakes are among the most delicate aquatic systems due to their limited size. The objective of this paper is to propose a System Dynamics model, employed in a real case study regarding the city of Rome and one of its water reserves, the Bracciano Lake, for the evaluation of different strategies and policies to reduce environmental impacts, considering different climatic and context scenarios. The results indicate that, as the system is currently exposed to a high risk of ecological disaster, the situation might worsen, and the disaster effectively happen. Simulation models may help agencies and administrations to explore policies and find solutions to address this fundamental problem, that may become even worst over the next years, given the potential severe consequences deriving from the current global warming trends

    Optical and radio survey of Southern Compact Groups of galaxies. I. Pilot study of six groups

    Full text link
    Multi-wavelength observations of Hickson's Compact Groups (HCGs) have shown that many of these groups are physical bound structures and are in different stage of evolution, from spiral-dominated systems to almost merged objects. Very few studies have analysed the Southern Compact Groups (SCGs) sample, which is though to be younger that HCGs, due to an on average higher number of spiral galaxies. We present here the first results from optical and radio observations on a pilot sample of SCGs.Comment: accepted on A&A on July 19, 2007. Figures 1 and 3-12 will be available only in electronic for
    corecore