A multi-wavelength pipeline for pulsar searches

Pulsar studies in the recent years have shown, more than others, to have benefited from a multi-wavelength approach. The INAF - Astronomical Observatory in Cagliari (INAF-OAC) is a growing facility with a young group devoted to pulsar and fast transients studies across the electromagnetic spectrum. Taking advantage of this expertise we have worked to provide a suite of multi-wavelength software and databases for the observations of pulsars and compact Galactic objects at the Sardinia Radio Telescope (SRT). In turn, radio pulsar observations at SRT will be made available, in a processed format, to gamma-ray searches using AGILE and Fermi gamma-ray satellite and, in a near future, they will be complementary to polarimetric X-ray observations with IXPE.Comment: Accepted for publications in Rendiconti Lincei as Proceedings of "A Decade of AGILE: Results, Challenges and Prospects of Gamma-Ray Astrophysics

GPU water cooling investigations for the digital correlator of the MeerKAT+

GPUs represent a valuable solution in the framework of digital signal processing in radio astronomy. Currently, GPUs have been selected as the primary option for building the digital correlator of the MeerKAT+ array, for both the F-Engine and the X/B-Engine. Thermal management is one of the major issues affecting GPUs in comparison to FPGAs and in this paper we outline how water cooling solutions may assist

Neuroplastic changes in c-Fos, ΔFosB, BDNF, trkB, and Arc expression in the hippocampus of male Roman rats: differential effects of sexual activity

Sexual activity causes differential changes in the expression of markers of neural activation (c-Fos and Delta FosB) and neural plasticity (Arc and BDNF/trkB), as determined either by Western Blot (BDNF, trkB, Arc, and Delta FosB) or immunohistochemistry (BDNF, trkB, Arc, and c-Fos), in the hippocam pus of male Roman high (RHA) and low avoidance (RLA) rats, two psychogenetically selected rat lines that display marked differences in sexual behavior (RHA rats exhibit higher sexual motivation and better copulatory performance than RLA rats). Both methods showed (with some differences) that sexual activity modifies the expression levels of these markers in the hippocampus of Roman rats depending on: (i) the level of sexual experience, that is, changes were usually more evident in sexually naive than in experienced rats; (ii) the hippocampal partition, that is, BDNF and Arc increased in the dorsal but tended to decrease in the ventral hippocampus; (iii) the marker considered, that is, in sexually experienced animals BDNF, c-Fos, and Arc levels were similar to those of controls, while Delta FosB levels increased; and (iv) the rat line, that is, changes were usually larger in RHA than RLA rats. These findings resemble those of early studies in RHA and RLA rats showing that sexual activity influences the expression of these markers in the nucleus accumbens, medial prefrontal cortex, and ventral tegmental area, and show for the first time that also in the hippocampus sexual activity induces neural activation and plasticity, events that occur mainly during the first phase of the acquisition of sexual experience and depend on the genotypic/phenotypic characteristics of the animals

Effect of acute administration of Pistacia lentiscus L. essential oil on rat cerebral cortex following transient bilateral common carotid artery occlusion

<p>Abstract</p> <p>Background</p> <p>Ischemia/reperfusion leads to inflammation and oxidative stress which damages membrane highly polyunsaturated fatty acids (HPUFAs) and eventually induces neuronal death. This study evaluates the effect of the administration of <it>Pistacia lentiscus </it>L. essential oil (E.O.), a mixture of terpenes and sesquiterpenes, on modifications of fatty acid profile and endocannabinoid (eCB) congener concentrations induced by transient bilateral common carotid artery occlusion (BCCAO) in the rat frontal cortex and plasma.</p> <p>Methods</p> <p>Adult Wistar rats underwent BCCAO for 20 min followed by 30 min reperfusion (BCCAO/R). 6 hours before surgery, rats, randomly assigned to four groups, were gavaged either with E.O. (200 mg/0.45 ml of sunflower oil as vehicle) or with the vehicle alone.</p> <p>Results</p> <p>BCCAO/R triggered in frontal cortex a decrease of docosahexaenoic acid (DHA), the membrane highly polyunsaturated fatty acid most susceptible to oxidation. Pre-treatment with E.O. prevented this change and led further to decreased levels of the enzyme cyclooxygenase-2 (COX-2), as assessed by Western Blot. In plasma, only after BCCAO/R, E.O. administration increased both the ratio of DHA-to-its precursor, eicosapentaenoic acid (EPA), and levels of palmytoylethanolamide (PEA) and oleoylethanolamide (OEA).</p> <p>Conclusions</p> <p>Acute treatment with E.O. before BCCAO/R elicits changes both in the frontal cortex, where the BCCAO/R-induced decrease of DHA is apparently prevented and COX-2 expression decreases, and in plasma, where PEA and OEA levels and DHA biosynthesis increase. It is suggested that the increase of PEA and OEA plasma levels may induce DHA biosynthesis via peroxisome proliferator-activated receptor (PPAR) alpha activation, protecting brain tissue from ischemia/reperfusion injury.</p

Data Reduction of Multi-wavelength Observations

We are developing a software to combine gamma-ray data from multiple telescopes with the aim to cross calibrate different instruments, test their data quality and to allow the confirmation of transient events using different instruments. In particular, we present the first applications using pulsar data from the AGILE and Fermi satellites and show how we solved the issues relative to combining different datasets and rescaling the parameters of different telescopes. In this way we extend the energy range observed by a single telescope and we can detect fainter objects. As a second step, we apply the technique of pulsar gating to the imaging data of the satellites combined, to look for pulsar wind nebulae. The same procedure is adopted in the radio domain, using data from the Sardinia Radio Telescope (SRT). We aim to be able to use similar techniques for multifrequency datasets spanning a large range of the electromagnetic spectrum. We also present the work in progress to include the automatic search for gamma-ray counterparts within the pipeline for pulsar search in radio

Sardinia Array Demonstrator: Instrument Overview and Status

In the framework of the Square Kilometer Array (SKA) project, the Italian Institute for Astrophysics (INAF) has addressed several efforts in the design and prototyping of aperture arrays for low-frequency radio astronomical research. The Sardinia Array Demonstrator (SAD) is a national project aimed to develop know-how in this area and to test different architectural technologies and calibration algorithms. SAD consists of 128 prototypical dual-polarized Vivaldi antennas designed to operate at radio frequencies below 650 MHz. The antennas will be deployed at the Sardinia Radio Telescope’s site with a versatile approach able to provide two different array configurations: (i) all antennas grouped in one large station or (ii) spread among a core plus few satellite stations. This paper provides an overview of the SAD project from an instrumental point of view, and illustrates its status after 2 years from its start

The high-frequency upgrade of the Sardinia Radio Telescope

We present the status of the Sardinia Radio Telescope (SRT) and its forthcoming update planned in the next few years. The post-process scenario of the upgraded infrastructure will allow the national and international scientific community to use the SRT for the study of the Universe at high radio frequencies (up to 116 GHz), both in single dish and in interferometric mode. A telescope like SRT, operating at high frequencies, represents a unique resource for the scientific community. The telescope will be ideal for mapping quickly and with relatively high angular resolution extended radio emissions characterized by low surface brightness. It will also be essential for spectroscopic and polarimetric studies of both Galactic and extragalactic radio sources. With the use of the interferometric technique, SRT and the other Italian antennas (Medicina and Noto) will operate within the national and international radiotelescope network, allowing astronomers to obtain images of radio sources at very high angular resolution

Status of the High-Frequency Upgrade of the Sardinia Radio Telescope

The Sardinia Radio Telescope is going through a major upgrade aimed at observing the universe at up to 116 GHz. A budget of 18.700.000 E has been awarded to the Italian National Institute of Astrophysics to acquire new state-of-the-art receivers, back-end, and high-performance computing, to develop a sophisticated metrology system and to upgrade the infrastructure and laboratories. This contribution draws the status of the whole project at eight months from the end of the funding scheme planned for August 2022

An observational study of 110 elderly lithium-treated patients followed up for 6 years with particular reference to renal function

BACKGROUND: Recent observational studies have focused on lithium treatment in the elderly, with particular reference to safety in terms of thyroid and renal functions. The purpose of this study was to compare the clinical characteristics of patients starting lithium treatment before (N = 79) or after (N = 31) the age of 65 years. Patients were followed up for 6 years with focus on renal function and prescription of levothyroxine and methimazole. RESULTS: At baseline, median lithium serum concentration was 0.55 mmol/l. The estimated glomerular filtration rate was lower than 60 ml/min/1.73 m2 in 43 (39%) patients. In a multiple regression analysis controlling for age and gender, we found a significant effect of duration of lithium treatment on estimated glomerular filtration rate (-0.85 ml/min/1.73 m2 per year of prior exposure). The annual decline during follow-up was 2.3 ml/min/1.73 m2. Two patients were prescribed levothyroxine, and two were prescribed methimazole for the first time during follow-up. CONCLUSIONS: Median lithium serum concentration in this cohort of elderly patients with mainly bipolar disorders was lower than the therapeutic range indicated for younger adults. The decline in glomerular filtration rate may be accelerated by long-term lithium use. Thyroid and renal functions continue to require close monitoring throughout the course of lithium treatment