3,324 research outputs found

    The relative concentration of visible and dark matter in clusters of galaxies

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    [Abridged] We consider two clusters (A496 and Coma) that are representative of the two classes of cool-core and non-cool-core clusters. We first refer to a two-component dynamical model that ignores the contribution from the galaxy density distribution and study the condition of hydrostatic equilibrium for the hot intracluster medium (ICM) under the assumption of spherical symmetry, in the presence of dark matter. We model the ICM density distribution in terms of a standard ÎČ\beta-model with ÎČ=2/3\beta=2/3, i.e. with a distribution similar to that of a regular isothermal sphere (RIS), and fit the observed X-ray brightness profiles. With the explicit purpose of ignoring cosmological arguments, we na\"ively assume that dark matter, if present, has an analogous density distribution, with the freedom of two different density and length scales. The relative distribution of visible and dark matter is then derived by fitting the temperature data for the ICM under conditions of hydrostatic equilibrium. For both clusters, we find that dark matter is more concentrated with respect to visible matter. We then test whether the conclusion changes significantly when dark matter is taken to be distributed according to cosmologically favored density profiles and when the contribution of the mass contained in galaxies is taken into account. Although the qualitative conclusions remain unchanged, we find that the contribution of galaxies to the mass budget is more important than generally assumed. We also show that, without resorting to additional information on the small scale, it is not possible to tell whether a density cusp is present or absent in these systems. [Abridged]Comment: 13 pages, 3 figures, accepted for publication in Il Nuovo Cimento

    The Role of the Tumor Suppressor Gene Protein Tyrosine Phosphatase Gamma in Cancer

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    Members of the Protein Tyrosine Phosphatase (PTPs) family are associated with growth regulation and cancer development. Acting as natural counterpart of tyrosine kinases (TKs), mainly involved in crucial signaling pathways such as regulation of cell cycle, proliferation, invasion and angiogenesis, they represent key parts of complex physiological homeostatic mechanisms. Protein tyrosine phosphatase gamma (PTPRG) is classified as a R5 of the receptor type (RPTPs) subfamily and is broadly expressed in various isoforms in different tissues. PTPRG is considered a tumor-suppressor gene (TSG) mapped on chromosome 3p14-21, a region frequently subject to loss of heterozygosity in various tumors. However, reported mechanisms of PTPRG downregulation include missense mutations, ncRNA gene regulation and epigenetic silencing by hypermethylation of CpG sites on promoter region causing loss of function of the gene product. Inactive forms or total loss of PTPRG protein have been described in sporadic and Lynch syndrome colorectal cancer, nasopharyngeal carcinoma, ovarian, breast, and lung cancers, gastric cancer or diseases affecting the hematopoietic compartment as Lymphoma and Leukemia. Noteworthy, in Central Nervous System (CNS) PTPRZ/PTPRG appears to be crucial in maintaining glioblastoma cell-related neuronal stemness, carving out a pathological functional role also in this tissue. In this review, we will summarize the current knowledge on the role of PTPRG in various human cancers

    Is the European Union (EU) Sustainable Finance Disclosure Regulation (SFDR) effective in shaping sustainability objectives? An analysis of investment funds' behaviour

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    This paper investigates how investment funds behave in line with European Union (EU)'s Sustainable Finance Disclosure Regulation (SFDR). The SFDR requires investment funds to take a clear position with respect to sustainability objectives, aiming at addressing the threats of greenwashing. However, we still do not know whether investment funds are managed accordingly. We frame our study within the organizational category theory, using Morningstar Direct data to analyze the category of investment funds declaring sustainability objectives - SFDR Article 9- and a control group with no sustainability objectives - SFDR Article 6. We assess how investment managers are financially incentivized to achieve either sustainability or financial objectives. The analysis evidences unexpected results: investment funds that self-select into opposite categories have incentives to behave similarly from both the financial and sustainability perspectives. Our results show that European investment funds hardly distinguish the attributes of sustainability meanings across opposite categories, reflecting category fuzziness

    Hydrogeological study of the monti sibillini north-western sector: a contribution to the official hydrogeologic mapping

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    This work underlines the importance of experimental data and integrates the hydrogeological mapping methods. The work has analyzed the lithological features of the outcropping rocks and their attitude to be crossed by the meteoric waters. Geologic-structural analysis has allowed to identify elements that can constitute the hydraulic barriers and the hydrogeological complexes that can contain the aquifers. A detailed analysis of base flow was carried out through hydrogeological survey directly performed in the river. The hydrogeological survey has allowed us: 1) to appraise the river's base flow; 2) to identify the punctual and linear springs; 3) to quantify the water resource on average drained; and 4) to determine the discharge regime of springs and rivers. The Conceptual Hydrogeological Model for each individual aquifer have been derived from geologic-structural analysis and hydrogeological studies. The Conceptual Hydrogeological Models allowed us to calculate the Mean Effective Infiltration (Ieff) of every aquifer. The values of Ieff are gathered in classes. All merged information has been used in the preparation of Hydrogeological Complexes and Natural Springs Map. The manifold hydrogeological information cannot be represented in one document only; so the Experimental Hydrogeological Mapping has been prepared as the overlap of different informative levels: Hydrogeological Complexes and Natural Springs Map (principal document), Surface Hydrology Map and Conceptual Hydrogeological Models of several recognized aquifers (complementary elements)

    Mass accretion rates of clusters of galaxies: CIRS and HeCS

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    We use a new spherical accretion recipe tested on N-body simulations to measure the observed mass accretion rate (MAR) of 129 clusters in the Cluster Infall Regions in the Sloan Digital Sky Survey (CIRS) and in the Hectospec Cluster Survey (HeCS). The observed clusters cover the redshift range of 0.01<z<0.300.01<z<0.30 and the mass range of ∌1014−1015h−1 M⊙\sim 10^{14}-10^{15} {h^{-1}~\rm{M_\odot}}. Based on three-dimensional mass profiles of simulated clusters reaching beyond the virial radius, our recipe returns MARs that agree with MARs based on merger trees. We adopt this recipe to estimate the MAR of real clusters based on measurements of the mass profile out to ∌3R200\sim 3R_{200}. We use the caustic method to measure the mass profiles to these large radii. We demonstrate the validity of our estimates by applying the same approach to a set of mock redshift surveys of a sample of 2000 simulated clusters with a median mass of M200=1014h−1 M⊙M_{200}= 10^{14} {h^{-1}~\rm{M_{\odot}}} as well as a sample of 50 simulated clusters with a median mass of M200=1015h−1 M⊙M_{200}= 10^{15} {h^{-1}~\rm{M_{\odot}}}: the median MARs based on the caustic mass profiles of the simulated clusters are unbiased and agree within 19%19\% with the median MARs based on the real mass profile of the clusters. The MAR of the CIRS and HeCS clusters increases with the mass and the redshift of the accreting cluster, which is in excellent agreement with the growth of clusters in the Λ\LambdaCDM model.Comment: 25 pages, 19 figures, 7 table

    Oocyte quality assessment in marine invertebrates: a novel approach by fluorescence spectroscopy

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    Background: The assessment of oocyte quality is, nowadays, a major challenge in aquaculture, oocyte cryopreservation, and environmental science. Oocyte quality is a determining factor in fertilization and embryo development; however, there is still a lack of rapid and sensitive cellular markers for its assessment. Currently, its estimation is predominantly based on morphological analysis, which is subjective and does not consistently reflect the developmental competence of the oocytes. Despite several recent studies investigating molecular markers related to oocyte quality, methods currently available for their determination pose various technical challenges and limitations. In this study, we developed a novel approach based on fluorescence spectroscopy to assess different intrinsic physiological parameters that can be employed to evaluate egg quality in marine invertebrates that are widely used as animal models such as sea urchins and mussels. Results: Different physiological parameters, such as viability, mitochondrial activity, intracellular ROS levels, plasma membrane lipid peroxidation, and intracellular pH, for egg quality evaluation have been successfully assessed in sea urchins and mussels by using specific fluorescent dyes and detecting the fluorescent signals in eggs through fluorescence spectroscopy. Conclusions: Based on our findings, we propose these physiological markers as useful predictors of egg quality in marine invertebrates; they can be estimated rapidly, selectively, and sensitively by employing this novel approach, which, due to the speed of analysis, the low cost, and easy use can be considered a powerful analytical tool for the egg quality assessment

    Pulses for healthy and sustainable food systems: The effect of origin on market price

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    Pulses are widely acknowledged for their high nutritional value due to high protein content, low content in calories, and low glycemic index; they are a good alternative to animal proteins thus offering a considerable number of social, environmental, and health benefits. Despite pulses being widely acknowledged as healthy and sustainable food, in mainly European countries, consumption is growing but still lower than the recommended level, production is unprofitable in comparison to the current market prices level, and a reduction in harvested area has led to a strong dependence on import for pulses supply. Pulses are particularly fitting to the feature of local food because they can be suitably grown in any context, even in the most complex areas, and consumer interest and awareness of food origin has strongly increased in recent years. Lentils were selected as a case study in this paper that aims to define which features are effective on market price and, in particular, the role of origin declaration on label plays in defining the market price and how the origin attributes may enhance market price and farms competitiveness. The methodological tool for this investigation is the hedonic price model, useful to explain the effects of attributes of pulses affecting the market price. Results contribute to a better understanding of the pulse market, emphasizing that the “origin declaration” on label may have a positive effect on market price

    Characterisation of hydraulic head changes and aquifer properties in the London Basin using Persistent Scatterer Interferometry ground motion data

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    In this paper, Persistent Scatterer Interferometry was applied to ERS-1/2 and ENVISAT satellite data covering 1992–2000 and 2002–2010 respectively, to analyse the relationship between ground motion and hydraulic head changes in the London Basin, United Kingdom. The integration of observed groundwater levels provided by the Environment Agency and satellite-derived displacement time series allowed the estimation of the spatio-temporal variations of the Chalk aquifer storage coefficient and compressibility over an area of ∌1360 km2. The average storage coefficient of the aquifer reaches values of 1 × 10−3 and the estimated average aquifer compressibility is 7.7 × 10−10 Pa−1 and 1.2 × 10−9 Pa−1 for the periods 1992–2000 and 2002–2010, respectively. Derived storage coefficient values appear to be correlated with the hydrogeological setting, where confined by the London Clay the storage coefficient is typically an order of magnitude lower than where the chalk is overlain by the Lambeth Group. PSI-derived storage coefficient estimates agree with the values obtained from pumping tests in the same area. A simplified one-dimensional model is applied to simulate the ground motion response to hydraulic heads changes at nine piezometers. The comparison between simulated and satellite-observed ground motion changes reveals good agreement, with errors ranging between 1.4 and 6.9 mm, and being 3.2 mm on average

    Presence and fate of microplastics in the water sources: focus on the role of wastewater and drinking water treatment plants

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    Microplastics are nowadays considered as ubiquitous pollutants since have been found widespread in all environmental compartments, particularly in the water sources. In the urban water cycle, the drinking water treatment plants and the wastewater treatment plants are the first and last barriers to microplastics pollution, respectively. The present work aims at presenting the information available on microplastic presence in the urban water cycle, reporting and linking what is known at the different stages. Focus is on the water sources and on the role of the water treatment plants as source and control of microplastics pollution. Aspects evaluated are microplastics abundance, characterization in terms of morphology, size and polymer composition, spatial and temporal variations, factors influencing their distribution and abundance, effects of treatments on their removal. Up to now there is no common framework for microplastics collection, sample pre-treatment, identification, quantification and classification. Data comparison is hindered due to the various analytical protocols implemented; hence the conclusions driven are mostly indicative or of very local significance. The available information is not evenly distributed among the urban water cycle components. For the establishment of proper microplastics pollution control strategies, the relative role of wastewater and drinking water treatment plants needs to be better deepened in terms of both quantity and quality effects. All these aspects are afforded in the present review which is based on the more recent data published by the specialized literature

    A proposal for compiling quantitative hydrogeological maps

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    An innovative approach to hydrogeological mapping based on quantitative analysis is shown in this paper. It gives some cartographical solutions for an immediate evaluation of the groundwater resources and their spatial distribution. All relevant aquifers, springs and their regime, geological and structural setting and their hydraulic role should be shown in several understandable and clear hydrogeological maps where all hydrogeological information is reported in detail in the “Hydrogeological experimental Map” composed by a. “Hydrogeological Complexes and Natural Springs Map”, b. “Surface Hydrology Map”, c. “Conceptual Hydrogeological Model” and d. “Hydrogeological sections”. The cartographical solutions adopted for representing all these documents are proposed in this paper. Some graphical solutions have been proposed for improving the Italian official guidelines of hydrogeological mapping at scale 1:50.000, explain the legends symbols and illustrate the structure of a hydrogeological GIS database. An application of this approach has been carried out in north-western sector of Sibillini Mts. (Marche, Italy)
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