83 research outputs found
Muons in the aftermath of neutron star mergers and their impact on trapped neutrinos
In the upcoming years, present and next-generation gravitational wave
observatories will detect a larger number of binary neutron star (BNS) mergers
with increasing accuracy. In this context, improving BNS merger numerical
simulations is crucial to correctly interpret the data and constrain the
equation of state (EOS) of neutron stars (NSs). State-of-the-art simulations of
BNS mergers do not include muons. However, muons are known to be relevant in
the microphysics of cold NSs and are expected to have a significant role in
mergers, where the typical thermodynamic conditions favour their production.
Our work is aimed at investigating the impact of muons on the merger remnant.
We post-process the outcome of four numerical relativity simulations of BNS
mergers performed with three different baryonic EOSs and two mass ratios
considering the first milliseconds after merger. We compute the abundance
of muons in the remnant and analyse how muons affect the trapped neutrino
component and the fluid pressure. We find that depending on the baryonic EOS,
the net fraction of muons is between and the net fraction of
electrons. Muons change the flavour hierarchy of trapped (anti-)neutrinos such
that deep inside the remnant, muon anti-neutrinos are the most abundant,
followed by electron anti-neutrinos. Finally, muons and trapped neutrinos
modify the neutron-to-proton ratio, affecting the remnant pressure by up to
when compared with calculations neglecting them. This work demonstrates
that muons have a non-negligible effect on the outcome of BNS merger
simulations, and they should be included to improve the accuracy of a
simulation.Comment: 19 pages, 11 figure
A postgraduate laboratory experiment to set up a single-photon detector using MKIDs
This paper presents a laboratory activity aimed at developing knowledge and
expertise in microwave applications at cryogenic temperatures. The experience
focuses on the detection of single infrared photons through Microwave Kinetic
Inductance Detectors (MKIDs). The experimental setup, theoretical concepts, and
activities involved are detailed, highlighting the skills and knowledge gained
through the experience. This experiment is designed for postgraduate students
in the field of quantum technologies.Comment: 16 pages, 11 figures, 1 box, submitted to European Journal of Physic
XKN: a Semi-analytic Framework for the Modelling of Kilonovae
After GW170817, kilonovae have become of great interest for the astronomical,
astrophysics and nuclear physics communities, due to their potential in
revealing key information on the compact binary merger from which they emerge,
such as the fate of the central remnant or the composition of the expelled
material. Therefore, the landscape of models employed for their analysis is
rapidly evolving, with multiple approaches being used for different purposes.
In this paper, we present xkn, a semi-analytic framework which predicts and
interprets the bolometric luminosity and the broadband light curves of such
transients. xkn models the merger ejecta structure accounting for different
ejecta components and non-spherical geometries. In addition to light curve
models from the literature based on time scale and random-walk arguments, it
implements a new model, xkn-diff, which is grounded on a solution of the
radiative transfer equation for homologously expanding material. In order to
characterize the variety of the ejecta conditions, it employs time and
composition dependent heating rates, thermalization efficiencies and opacities.
We compare xkn light curves with reference radiative transfer calculations, and
we find that xkn-diff significantly improves over previous semi-analytic
prescriptions. We view xkn as an ideal tool for extensive parameter estimation
data analysis applications.Comment: 16 pages, 7 figure
Molecular Portrait of Clear Cell Renal Cell Carcinoma: An Integrative Analysis of Gene Expression and Genomic Copy Number Profiling
Renal cell carcinoma (RCC) incidence accounts for about 3 to 10 cases per 100,000 individuals with a predilection for adult males over 60 year old (1.6:1 male/female ratio) (Chow, 2010; Nese, 2009). In Europe, about 60,000 individuals are affected by RCC every year, with a mortality rate of about 18,000 subjects and an incidence rate for all stages steadily rising over the last three decades. Although inherited forms occur in a number of familial cancer syndromes, as the well-known von Hippel-Lindau (VHL) syndrome, RCC is commonly sporadic (Cohen & McGovern, 2005; Kaelin, 2007) and, as recently highlighted by the National Cancer Institute (NCI), influenced by the interplay between exposure to environmental risk factors and genetic susceptibility of exposed individuals (Chow et al., 2010). Being poorly symptomatic in early phases, many cases become clinically detectable only when already advanced and, as such, therapy-resistant (Motzer, 2011). Based on histology, RCC can be classified into several subtypes, i.e., clear cell (80% of cases), papillary (10%), chromophobe (5%) and oncocytoma (5%), each one characterized by specific histo- pathological features, malignant potential and clinical outcome (Cohen & McGovern, 2005). Patient stratification is normally achieved using prognostic algorithms and nomograms based on multiple clinico-pathological factors such as TNM stage, Fuhrman nuclear grade, tumor size, performance status, necrosis and other hematological indices (Flanigan et al., 2011), although the most efficient predictors of survival and recurrence are based on nuclear grade alone (Nese et al., 2009). As recently reviewed by Brannon et al. (Brannon & Rathmell, 2010), a finer RCC subtype classification could be obtained exploiting the vast amount of genomic and transcriptional data that have been presented in numerous studies. For instance, several authors proposed a molecular classification of RCC based on differential gene expression profiles, with any subtype characterized by the activation of distinct gene sets (Brannon, 2010; Furge, 2004; Skubitz, 2006; Su\u308ltmann, 2005; Zhang, 2008), while others identified RCC-specific biomarkers (e.g. CA9, ki67, VEGF proteins, phosphorylated AKT, PTEN, HIF-1). Lately, it has been reported that microRNAs, a small class of non coding RNA molecules, could contribute to RCC development at different levels and may represent a new group of potential tumor biomarkers (Redova et al., 2011). Despite the numerous efforts in dissecting the molecular features of RCC through functional genomics, not a single transcriptional signature or biomarker has gained approval for clinical application yet (Arsanious, 2009; Eichelberg, 2009; Lam, 2007; Yin-Goen, 2006), so that the identification of novel molecular markers to improve early diagnosis and prognostic prediction and of candidate targets to develop new therapeutic approaches remains of primary importance for this pathology
A comparative analysis of the mobility of 45 proteins in the synaptic bouton
Many proteins involved in synaptic transmission are well known, and their features, as their abundance or spatial distribution, have been analyzed in systematic studies. This has not been the case, however, for their mobility. To solve this, we analyzed the motion of 45 GFP-tagged synaptic proteins expressed in cultured hippocampal neurons, using fluorescence recovery after photobleaching, particle tracking, and modeling. We compared synaptic vesicle proteins, endo- and exocytosis cofactors, cytoskeleton components, and trafficking proteins. We found that movement was influenced by the protein association with synaptic vesicles, especially for membrane proteins. Surprisingly, protein mobility also correlated significantly with parameters as the protein lifetimes, or the nucleotide composition of their mRNAs. We then analyzed protein movement thoroughly, taking into account the spatial characteristics of the system. This resulted in a first visualization of overall protein motion in the synapse, which should enable future modeling studies of synaptic physiology
Geomorphology of the northwestern Kurdistan Region of Iraq: landscapes of the Zagros Mountains drained by the Tigris and Great Zab Rivers
We present the geomorphological map of the northwestern part of the Kurdistan Region of
Iraq, where the landscape expresses the tectonic activity associated with the Arabia-Eurasia
convergence and Neogene climate change. These processes influenced the evolution of
landforms and fluvial pathways, where major rivers Tigris, Khabur, and Great Zab incise the
landscape of Northeastern Mesopotamia Anticlinal ridges and syncline trough compose the
Zagros orogen. The development of water and wind gaps, slope, and karsts processes in the
highlands and the tilting of fluvial terraces in the flat areas are the main evidence of the
relationship between tectonics, climate variations and geomorphological processes. During
the Quaternary, especially after the Last Glacial Maximum, fluctuating arid and wet periods
also influenced local landforms and fluvial patterns of the area. Finally, the intensified
Holocene human occupation and agricultural activities during the passage to more complex
societies over time impacted the evolution of the landscape in this part of Mesopotamia
Renal cell carcinoma primary cultures maintain genomic and phenotypic profile of parental tumor tissues
<p>Abstract</p> <p>Background</p> <p>Clear cell renal cell carcinoma (ccRCC) is characterized by recurrent copy number alterations (CNAs) and loss of heterozygosity (LOH), which may have potential diagnostic and prognostic applications. Here, we explored whether ccRCC primary cultures, established from surgical tumor specimens, maintain the DNA profile of parental tumor tissues allowing a more confident CNAs and LOH discrimination with respect to the original tissues.</p> <p>Methods</p> <p>We established a collection of 9 phenotypically well-characterized ccRCC primary cell cultures. Using the Affymetrix SNP array technology, we performed the genome-wide copy number (CN) profiling of both cultures and corresponding tumor tissues. Global concordance for each culture/tissue pair was assayed evaluating the correlations between whole-genome CN profiles and SNP allelic calls. CN analysis was performed using the two CNAG v3.0 and Partek software, and comparing results returned by two different algorithms (Hidden Markov Model and Genomic Segmentation).</p> <p>Results</p> <p>A very good overlap between the CNAs of each culture and corresponding tissue was observed. The finding, reinforced by high whole-genome CN correlations and SNP call concordances, provided evidence that each culture was derived from its corresponding tissue and maintained the genomic alterations of parental tumor. In addition, primary culture DNA profile remained stable for at least 3 weeks, till to third passage. These cultures showed a greater cell homogeneity and enrichment in tumor component than original tissues, thus enabling a better discrimination of CNAs and LOH. Especially for hemizygous deletions, primary cultures presented more evident CN losses, typically accompanied by LOH; differently, in original tissues the intensity of these deletions was weaken by normal cell contamination and LOH calls were missed.</p> <p>Conclusions</p> <p>ccRCC primary cultures are a reliable <it>in vitro </it>model, well-reproducing original tumor genetics and phenotype, potentially useful for future functional approaches aimed to study genes or pathways involved in ccRCC etiopathogenesis and to identify novel clinical markers or therapeutic targets. Moreover, SNP array technology proved to be a powerful tool to better define the cell composition and homogeneity of RCC primary cultures.</p
Science with the Einstein Telescope: a comparison of different designs
The Einstein Telescope (ET), the European project for a third-generation
gravitational-wave detector, has a reference configuration based on a
triangular shape consisting of three nested detectors with 10 km arms, where in
each arm there is a `xylophone' configuration made of an interferometer tuned
toward high frequencies, and an interferometer tuned toward low frequencies and
working at cryogenic temperature. Here, we examine the scientific perspectives
under possible variations of this reference design. We perform a detailed
evaluation of the science case for a single triangular geometry observatory,
and we compare it with the results obtained for a network of two L-shaped
detectors (either parallel or misaligned) located in Europe, considering
different choices of arm-length for both the triangle and the 2L geometries. We
also study how the science output changes in the absence of the low-frequency
instrument, both for the triangle and the 2L configurations. We examine a broad
class of simple `metrics' that quantify the science output, related to compact
binary coalescences, multi-messenger astronomy and stochastic backgrounds, and
we then examine the impact of different detector designs on a more specific set
of scientific objectives.Comment: 197 pages, 72 figure
The Botanical Record of Archaeobotany Italian Network - BRAIN: a cooperative network, database and website
Con autorizaciĂłn de la revista para autores CSIC[EN] The BRAIN (Botanical Records of Archaeobotany Italian Network) database and network was developed by the cooperation of archaeobotanists working on Italian archaeological sites. Examples of recent research including pollen or other plant remains in analytical and synthetic papers are reported as an exemplar reference list. This paper retraces the main steps of the creation of BRAIN, from the scientific need for the first research cooperation to the website which has a free online access since 2015.Peer reviewe
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