127 research outputs found

    The environment of AGN along the quasar main sequence

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    openThe analysis was carried out for a sample of 680 AGN, chose along the quasar main sequence, so with different values of H_beta FWHM. Was considered an area around each source of 0.5 Mpc, in which we analyzed the behaviour of the objects inside that area. Were kept only galaxies and AGN as possible closer companions, instead the other objects which are contaminants were discarded. Were performed some analyses in order to understand if each object is really a closer companion or only a backgroud/foreground sorce. The principal aim is to investigate if the physical companions may affect the evolution and the behaviour of the source at the centre, and undertand what are the difference, based on the environment, of the sources along the main sequence. Different statistical analyses were performed, in order to avoid any sort of false positive in the companions research, and to make a correction on the studies.The analysis was carried out for a sample of 680 AGN, chose along the quasar main sequence, so with different values of H_beta FWHM. Was considered an area around each source of 0.5 Mpc, in which we analyzed the behaviour of the objects inside that area. Were kept only galaxies and AGN as possible closer companions, instead the other objects which are contaminants were discarded. Were performed some analyses in order to understand if each object is really a closer companion or only a backgroud/foreground sorce. The principal aim is to investigate if the physical companions may affect the evolution and the behaviour of the source at the centre, and undertand what are the difference, based on the environment, of the sources along the main sequence. Different statistical analyses were performed, in order to avoid any sort of false positive in the companions research, and to make a correction on the studies

    Narrow-Line Seyfert 1 Galaxies With Absorbed Jets–Insights From Radio Spectral Index Maps

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     Narrow-line Seyfert 1 (NLS1) galaxies are active galactic nuclei (AGN) believed to be in the early stages of their evolution. A fraction of them have been found to host relativistic jets. Due to the lack of large-scale diffuse radio emission they are believed to be experiencing one of their first activity cycles, and can offer us an opportunity to study the early evolution of more powerful AGN, such as radio galaxies and flat-spectrum radio quasars. Recently, a group of intriguing jetted NLS1s was discovered: based on high radio frequency data they host relativistic jets, but in the JVLA observations they all showed steep radio spectra at least up to 9.0 GHz, indicating very strong absorption at these frequencies. In this paper we study a subset of these sources in detail by employing spatially resolved radio spectral index maps at central frequencies of 1.6, 5.2, and 9.0 GHz. With spectral index maps we can disentangle the different radio emission components over the radio-emitting region, and get insights into the production mechanisms of radio emission. In addition, we study their host galaxies in relation to the radio emission to investigate if the host can provide us additional information regarding the origin of the radio emission, or the launching mechanism of the jets. It is fascinating how different the sources studied are, and certainly more, especially wide frequency-range, and high-resolution observations will be needed to understand their history and current properties, such as the reason behind the extraordinary radio spectra.</p

    Divergent thinking abilities in frontotemporal dementia: A mini-review

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    A large number of studies, including single case and case series studies, have shown that patients with different types of frontotemporal dementia (FTD) are characterized by the emergence of artistic abilities. This led to the hypothesis of enhanced creative thinking skills as a function of these pathological conditions. However, in the last years, it has been argued that these brain pathologies lead only to an augmented \u201cdrive to produce\u201d rather than to the emergence of creativity. Moreover, only a few studies analyzed specific creative skills, such as divergent thinking (DT), by standardized tests. This Mini-Review aimed to examine the extent to which DT abilities are preserved in patients affected by FTD. Results showed that DT abilities (both verbal and figural) are altered in different ways according to the specific anatomical and functional changes associated with the diverse forms of FTD. On the one hand, patients affected by the behavioral form of FTD can produce many ideas because of unimpaired access to memory stores (i.e., episodic and semantic), but are not able to recombine flexibly the information to produce original ideas because of damages in the pre-frontal cortex. On the other hand, patients affected by the semantic variant are impaired also in terms of fluency because of the degradation of their semantic memory store. Potential implications, limitations, and future research directions are discussed

    A Comparison of Divergent Thinking Abilities Between Healthy Elderly Subjects and MCI Patients: Preliminary Findings and Implications

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    Objective: Divergent thinking (DT) has attracted research interest because of its potential role in early diagnosis and rehabilitation programs for patients affected by neurodegenerative diseases. Recently, DT has received even more attention because of its proven relationship with cognitive reserve (CR) and the possibility of a standardized assessment. However, few studies have investigated this ability in dementia patients, and even less is known about patients affected by Mild Cognitive Impairment (MCI). Thus, this study aims to investigate DT abilities in MCI patients. Methods: A total of 25 MCI patients and 25 healthy controls subjects (HC; from a random selection of 50) matched for age, gender, and educational level were enrolled. General cognitive functioning was measured by the Montreal Cognitive Assessment (MoCA), while the Abbreviated Torrance Test for Adults (ATTA) was selected to measure DT. Results: MANOVA analysis did not reveal any significant differences in DT abilities between MCI patients and HC except for the figural indicator score. A logistic hierarchical regression analysis revealed that the figural indicator score added an 8% of accuracy in the prediction of the group variable over the general cognition measure (MoCA). Conclusion: MCI patients seem to perform significantly worse than HC only in the figural DT score and this evidence has significant practical implications. First, that figural DT seemed to decrease even earlier than verbal DT and could therefore be taken into account for early diagnosis of MCI patients. On the contrary, the sparing of all the other DT skills (such as verbal DT skills, fluency, flexibility, originality, and elaboration) may suggest that, given its relationship with CR, verbal DT could instead be considered a possible target for prevention or early cognitive stimulation interventions

    Conservation status and historical relatedness of Italian cattle breeds

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    Abstract Background: In the last 50 years, the diversity of cattle breeds has experienced a severe contraction. However, in spite of the growing diffusion of cosmopolite specialized breeds, several local cattle breeds are still farmed in Italy. Genetic characterization of breeds represents an essential step to guide decisions in the management of farm animal genetic resources. The aim of this work was to provide a high-resolution representation of the genome-wide diversity and population structure of Italian local cattle breeds using a medium-density single nucleotide polymorphism (SNP) array. Results: After quality control filtering, the dataset included 31,013 SNPs for 800 samples from 32 breeds. Our results on the genetic diversity of these breeds agree largely with their recorded history. We observed a low level of genetic diversity, which together with the small size of the effective populations, confirmed that several breeds are threatened with extinction. According to the analysis of runs of homozygosity, evidence of recent inbreeding was strong in some local breeds, such as Garfagnina, Mucca Pisana and Pontremolese. Patterns of genetic differentiation, shared ancestry, admixture events, and the phylogenetic tree, all suggest the presence of gene flow, in particular among breeds that originate from the same geographical area, such as the Sicilian breeds. In spite of the complex admixture events that most Italian cattle breeds have experienced, they have preserved distinctive characteristics and can be clearly discriminated, which is probably due to differences in genetic origin, environment, genetic isolation and inbreeding. Conclusions: This study is the first exhaustive genome-wide analysis of the diversity of Italian cattle breeds. The results are of significant importance because they will help design and implement conservation strategies. Indeed, efforts to maintain genetic diversity in these breeds are needed. Improvement of systems to record and monitor inbreeding in these breeds may contribute to their in situ conservation and, in view of this, the availability of genomic data is a fundamental resource

    Graphene-based ultra-wide band printed bow-tie antenna for remote tracking

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    Printed antennas are cheap, lightweight, easy to- fabricate with high precision, and adaptable to mass production. These features are desirable for both indoor and outdoor handheld UWB antenna applications. In this paper, we consider planar versions of a high performance ultra-wide band bow-tie antenna with omnidirectional radiation characteristics

    Long-Term Optical Monitoring of Broad-Line AGNs (LoTerm AGN): Case Study of NGC 3516

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    Properties of the broad line region (BLR) in active galactic nuclei (AGNs) are commonly used to estimate the mass of the supermassive black hole (SMBH) that powers an AGN. However, the understanding of the physics behind the BLR remains incomplete. The AGNs exhibit strong optical variability, observed in the change of the profiles and fluxes of broad emission lines. Utilizing this variability provides an opportunity to constrain the physics of the BLR, and understand the interplay of the BLR with SMBH and surrounding regions. Here, we present the long-term monitoring campaign of a sample of the known broad-line AGNs (identified as LoTerm AGN). The aim of this study is to show the importance of sustained and dedicated campaigns that continually collect spectroscopic data of the known AGNs over extended timescales, providing unique insight into the origin and structure of the BLR. LoTerm AGN is a collaborative network of seven moderate-size telescopes equipped for spectroscopy. We focus on the recent spectral data of the known changing-look AGN, NGC 3516. Specifically, we examine the broad hydrogen Balmer H&alpha; line observed in the period 2020&ndash;2023, demonstrating that this AGN remains active with the BLR signatures observed in the spectra. No significant change in the broad line profile of H&alpha; line is observed during this recent period
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