3,351 research outputs found
The relative concentration of visible and dark matter in clusters of galaxies
[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 -model with , 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
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
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
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)
Oocyte quality assessment in marine invertebrates: a novel approach by fluorescence spectroscopy
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
Mass accretion rates of clusters of galaxies: CIRS and HeCS
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
and the mass range of . 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 .
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 as well as a sample
of 50 simulated clusters with a median mass of : the median MARs based on the caustic mass profiles of
the simulated clusters are unbiased and agree within 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
CDM model.Comment: 25 pages, 19 figures, 7 table
Pulses for healthy and sustainable food systems: The effect of origin on market price
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 âorigin declarationâ 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
In this paper, Persistent Scatterer Interferometry was applied to ERS-1/2 and ENVISAT satellite data covering 1992â2000 and 2002â2010 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 âŒ1360 km2. The average storage coefficient of the aquifer reaches values of 1 Ă 10â3 and the estimated average aquifer compressibility is 7.7 Ă 10â10 Paâ1 and 1.2 Ă 10â9 Paâ1 for the periods 1992â2000 and 2002â2010, 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
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
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 âHydrogeological experimental
Mapâ composed by a. âHydrogeological Complexes and
Natural Springs Mapâ, b. âSurface Hydrology Mapâ, c. âConceptual
Hydrogeological Modelâ and d. âHydrogeological sectionsâ.
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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