465 research outputs found
Barycentered NICER event list from ObsID 1200120106, used in Stingray tutorial
No full text<p>This is a NASA NICER observation of the accreting black hole MAXI 1820+070 during its 2018 outburst</p>
<p>The raw X-ray event data in FITS format were obtained from the NICER archive at HEASARC:</p>
<p>https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3hdprods.pl?files=Preview&Coordinates=Equatorial&Equinox=2000&CheckSize=1&showgifs=1&Target=heasarc%5Fnicermastr%7C%7C%7C%5F%5Frow%3D30877%7C%7C&popupFrom=&querytime=1708425079</p>
<p>Processing: <br>We ran the barycorr FTOOL, using the JPL DE 430 ephemeris (all details of processing can be found in the header of the FITS file). </p>
<p>We distribute it to be used as practice data for Spectral Timing tutorials. Scientific use might require better processing, involving a re-run of the Level-2 data pipeline.</p>
The high energy X-ray probe (HEX-P): studying extreme accretion with ultraluminous X-ray sources
No full textIntroduction: ultraluminous X-ray sources (ULXs) represent an extreme class of accreting compact objects: from the identification of some of the accretors as neutron stars to the detection of powerful winds travelling at 0.1–0.2 c, the increasing evidence points towards ULXs harbouring stellar-mass compact objects undergoing highly super-Eddington accretion. Measuring their intrinsic properties, such as the accretion rate onto the compact object, the outflow rate, the masses of accretor/companion-hence their progenitors, lifetimes, and future evolution-is challenging due to ULXs being mostly extragalactic and in crowded fields. Yet ULXs represent our best opportunity to understand super-Eddington accretion physics and the paths through binary evolution to eventual double compact object binaries and gravitational-wave sources.Methods: through a combination of end-to-end and single-source simulations, we investigate the ability of HEX-P to study ULXs in the context of their host galaxies and compare it to XMM-Newton and NuSTAR, the current instruments with the most similar capabilities.Results: HEX-P’s higher sensitivity, which is driven by its narrow point-spread function and low background, allows it to detect pulsations and broad spectral features from ULXs better than XMM-Newton and NuSTAR.Discussion: we describe the value of HEX-P in understanding ULXs and their associated key physics, through a combination of broadband sensitivity, timing resolution, and angular resolution, which make the mission ideal for pulsation detection and low-background, broadband spectral studies
Complementary feed for the control of pruritus in atopic dermatitis in dogs
No full textPruritus is a common manifestation in dogs with allergic skin diseases and itching can significantly affect the
quality of life of both affected animals and their owners, with even severe repercussions [1]. Pharmacological treatments and complementary feeds that are able to control itching quickly and in the long run are in great demand
and attract the attention of many researchers and companies. The aim of this study was to assess the effectiveness
of a complementary feed containing flavonoids, stilbenes, and cannabinoids (obtained from vegetable/botanical by- products/vegetable/botanical source) in the control of itching in dogs suffering from atopic dermatitis. Such complementary feed has been shown to be able to reduce the gene expression of ccl2, ccl17, il31ra and tslp in an experimental in vitro model of atopic dermatitis [3]. The primary efficacy endpoint was the reduction of CADESI-04
and pruritus visual analogue scale (pVas) scores. The study protocol was successfully submitted to the Animal Welfare Body of the University of Camerino (protocol code 10/2021). Ten dogs affected by atopic dermatitis, diagnosed according to current guidelines [1, 2], received a hypoallergenic food for the duration of the study. Once enrolled, in the first 6 weeks dogs received the administration of oclacitinib (Apoquel®, Zoetis) twice daily for two weeks and then once daily for 4 weeks. Starting from the fifth week, the administration of complementary feed began, according to the following dosage: twice daily for two weeks and then once daily for 8 weeks. Administration
of oclacitinib was discontinued at week 6 in all dogs enrolled in the study, who received the complementary feed up to week 12. In all dogs there was a marked reduction in both CADESI-04 and owner-reported pVas for pruritus in
the first four weeks of oclacitinib administration. In the fifth and sixth week of the study (oclacitinib + complementary feed) the trend of CADESI-04 and pVas was the same, as well as from the seventh week onwards for all dogs enrolled in the study. Although data collected are only preliminary, it is possible to highlight that the
complementary feed effectively control itching in supplemented dogs, which did not show any adverse event. This study further confirm the ability of selected complementary feed to control dermatological disease manifestation in dogs [4].
COMPLEMENTARY FEED FOR THE CONTROL OF PRURITUS IN ATOPIC DERMATITIS IN DOGS
Andrea Marchegiani (1), Alessandro Fruganti (1), Elena Dalle Vedove (2), Benedetta Bachetti (2), Marcella Massimini (2), Cataldo Ribecco (2), Matteo Cerquetella (1), AndreaSpaterna (1)
(1) Università degli Studi di Camerino, Scuola di Bioscienze e Medicina Veterinaria. (2) Research and Development Unit (NIL), C.I.A.M. srl.
Corresponding author: A. Marchegiani ([email protected])
[1] Favrot C et al. A prospective study on the clinical features of chronic canine atopic dermatitis and its diagnosis. Vet Dermatol, 21:23–31, 2010.
[2] Hensel P et al. Canine atopic dermatitis: detailed guidelines for diagnosis and allergen identification. BMC Vet Res, 11(1):196, 2015.
[3] Massimini M et al. Polyphenols and Cannabidiol Modulate Transcriptional Regulation of Th1/Th 2 Inflammatory Genes Related to Canine Atopic Dermatitis. Front Vet Sci, 8:1–14, 2021.
[ 4] M arc hegi ani A et al . Im pac t o f N utri ti o na l Supplementation on Canine Dermatological Disorders. Vet Sci MDPI, 38:1–13, 2020
No Time for Dead Time: Use the Fourier Amplitude Differences to Normalize Dead-time-affected Periodograms
No full textDead time affects many of the instruments used in X-ray astronomy, by producing a strong distortion in power density spectra. This can make it difficult to model the aperiodic variability of the source or look for quasi-periodic oscillations. Whereas in some instruments a simple a priori correction for dead-time-affected power spectra is possible, this is not the case for others such as NuSTAR, where the dead time is non-constant and long (~2.5 ms). Bachetti et al. (2015) suggested the cospectrum obtained from light curves of independent detectors within the same instrument as a possible way out, but this solution has always only been a partial one: the measured rms was still affected by dead time because the width of the power distribution of the cospectrum was modulated by dead time in a frequency-dependent way. In this Letter, we suggest a new, powerful method to normalize dead-time-affected cospectra and power density spectra. Our approach uses the difference of the Fourier amplitudes from two independent detectors to characterize and filter out the effect of dead time. This method is crucially important for the accurate modeling of periodograms derived from instruments affected by dead time on board current missions like NuSTAR and Astrosat, but also future missions such as IXPE
NuSTAR DETECTION OF HARD X-RAY PHASE LAGS FROM THE ACCRETING PULSAR GS 0834−430
No full textAuthors: - Hiromasa Miyasaka, Matteo Bachetti, Fiona A. Harrison, Felix Fürst, Didier Barret, Eric C. Bellm, Steven E. Boggs, Deepto Chakrabarty, Jerome Chenevez, Finn E. Christensen, William W. Craig, Brian W. Grefenstette, Charles J. Hailey, Kristin K. Madsen, Lorenzo Natalucci, Katja Pottschmidt, Daniel Stern, John A. Tomsick, Dominic J. Walton, Jörn Wilms, and William ZhangThe Nuclear Spectroscopic Telescope Array hard X-ray telescope observed the transient Be/X-ray binary GS 0834−430 during its 2012 outburst—the first active state of this system observed in the past 19 yr. We performed timing and spectral analysis and measured the X-ray spectrum between 3–79 keV with high statistical significance. We find the phase-averaged spectrum to be consistent with that observed in many other magnetized, accreting pulsars. We fail to detect cyclotron resonance scattering features that would allow us to constrain the pulsar's magnetic field in either phase-averaged or phase-resolved spectra. Timing analysis shows a clearly detected pulse period of ∼12.29 s in all energy bands. The pulse profiles show a strong, energy-dependent hard phase lag of up to 0.3 cycles in phase, or about 4 s. Such dramatic energy-dependent lags in the pulse profile have never before been reported in high-mass X-ray binary pulsars. Previously reported lags have been significantly smaller in phase and restricted to low energies (E < 10 keV). We investigate the possible mechanisms that might produce this energy-dependent pulse phase shift. We find the most likely explanation for this effect is a complex beam geometry.This work was supported under NASA contract No. NNG08FD60C and made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations, Software, and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). Matteo Bachetti wishes to acknowledge the support from the Centre National d'Etudes Spatiales (CNES). Lorenzo Natalucci acknowledges financial support through contract ASI/INAF I/037/12/0.https://iopscience.iop.org/article/10.1088/0004-637X/775/1/6
Beyond translation: systematic insight of the multifaceted roles of GARS1 in cellular biology and disease
No full textHuman glycyl-tRNA synthetase (GARS), encoded by the GARS1 gene, is a key protein within the aminoacyl-tRNA synthetases family, responsible for catalyzing the attachment of glycine to its corresponding tRNA during protein synthesis. While aminoacyl-tRNA synthetases are primarily known for their role in translation, emerging evidence indicates that they also have non-canonical functions in physiological and pathological processes, including metabolism, angiogenesis, immune responses, and inflammation. This review integrates glycyl-tRNA synthetase evolutionary origins, isoform biology, structure function relationships, immune roles, and cellular stress evidence across bladder, prostate, breast, colorectal, and hepatocellular tumors. Unlike prior papers about GARS, we (i) distinguish cytosolic vs mitochondrial GARS isoforms and their detection pitfalls; (ii) synthesize non-canonical mechanisms (neddylation interfaces, extracellular vesicles-mediated C-ter and N-ter peptides, CDH6-dependent signaling); and (iii) provide a comparative reliability map across cancers, identifying urinary bladder cancer as the most substantiated indication with convergent transcriptomic, proteomic, metabolic, and preliminary translational evidence. Current literature is dominated by correlative and in-vitro studies, and prospective clinical validation is scarce. GARS is a promising but incompletely defined oncologic and immunobiologic node; targeted, standardized, and clinically anchored studies are now feasible and necessary
NuSTAR detection of 4s Hard X-ray Lags from the Accreting Pulsar GS 0834-430
No full textAuthors: - Matteo Bachetti, Hiromasa Miyasaka, Fiona Harrison, Felix Fürst, Didier Barret, Eric C. Bellm, Steven E. Boggs, Deepto Chakrabarty, Jerome Chenevez, Finn E. Christensen, William W. Craig, Brian W. Grefenstette, Charles J. Hailey, Kristin K. Madsen, Lorenzo Natalucci, Katja Pottschmidt, Daniel Stern, John A. Tomsick, Dominic J. Walton, Jörn Wilms, and William ZhangEPJ Web of Conferences, 2014The NuSTAR hard X-ray telescope observed the transient Be/X-ray binary GS 0834–430 during its 2012 outburst. The source is detected between 3 – 79 keV with high statistical significance, and we were able to perform very accurate spectral and timing analysis. The phase-averaged spectrum is consistent with that observed in many other magnetized accreting pulsars. We fail to detect cyclotron resonance scattering features in either phase-averaged nor phase-resolved spectra that would allow us to constrain the pulsar’s magnetic field. We detect a pulse period of ~ 12:29 s in all energy bands. The pulse profile can be modeled with a double Gaussian and shows a strong and smooth hard lag of up to 0.3 cycles in phase, or about 4s between the pulse at ~ 3 and ≳ 30 keV. This is the first report of such a strong lag in high-mass X-ray binary (HMXB) pulsars. Previously reported lags have been significantly smaller in phase and restricted to low-energies (E<10 keV). We investigate the possible mechanisms that might produce such lags. We find the most likely explanation for this effect to be a complex beam geometry.https://www.epj-conferences.org/articles/epjconf/abs/2014/01/epjconf_mag2013_06011/epjconf_mag2013_06011.htm
HEX-P: The High-Energy X-ray Probe
No full textAuthors: - Kristin K. Madsen, Ryan Hickox, Matteo Bachetti, Daniel Stern, Nis C. Gellert, Javier García, Erin Kara, N. W. Brandt, Henric Krawczynski, Anne Lohfink, Laura Brenneman, F. Christensen, Matthew Middleton, A. Hornstrup, Giorgio Matt, Amruta Jaodand, George Lansbury, Claudio Ricci, Felix Fuerst, David Ballantyne, Dom Walton, Andy Fabian, D. Ferreira, Katja Pottschmidt, Jon M. Miller, David L. Windt, Mislav Baloković, Nikita Kamraj, Joern Wilms, Marianne Heida, David Alexander, Peter Boorman, Daniel Wik, Julia Vogel, Hannah Earnshaw, Marie-Anne Descalle, Francesca Civano, Francesca Fornasini, Jonathan Grindlay, William Zhang, Ann Hornschemeier, William CraigThe High-Energy X-ray Probe (HEX-P) is a next-generation high-energy X-ray observatory
with broadband (2-200 keV) response that has 40 times the sensitivity of any previous mission
in the 10-80 keV band and > 100 times the sensitivity of any previous mission in the 80-200
keV band. With this leap in observational capability, HEX-P will address a broad range of
science objectives beyond any planned mission in the hard X-ray bandpass. HEX-P will probe
the extreme environments around black holes and neutron stars, map the growth of
supermassive black holes, and quantify the effect they have on their environments. HEX-P
will resolve the hard X-ray emission from dense regions of our Galaxy to understand the highenergy source populations and investigate dark matter candidate particles through their decay
channel signatures. If developed and launched on a timescale similar to Athena, the
complementary abilities of the two missions will greatly enhance the Community’s ability to
address the important science questions of the hot universe. HEX-P addresses science that is
not planned by any flagship-class missions, and is beyond the capability of an Explorer-class
mission.https://orbit.dtu.dk/en/publications/hex-p-the-high-energy-x-ray-prob
Beneficial Effect of Phenytoin and Carbamazepine on GFAP Gene Expression and Mutant GFAP Folding in a Cellular Model of Alexander's Disease
No full textAlexander's disease (AxD) is a rare, usually relentlessly progressive disorder of astroglial cells in the central nervous system related to mutations in the gene encoding the type III intermediate filament protein, glial fibrillary acidic protein (GFAP). The pathophysiology of AxD is only partially understood. Available data indicate that an excessive GFAP gene expression may play a role. In particular, a "threshold hypothesis" has been reported, suggesting that mutant GFAP representing about 20% of the total cellular GFAP should be sufficient to cause disease. Thus, strategies based on reducing cellular mutant GFAP protein levels and/or activating biological processes involved in the correct protein folding could be effective in counteracting the toxic effect of misfolded GFAP. Considering that clomipramine (CLM), which has been selected by a wide small molecules screening as the greatest inhibitory potential drug against GFAP expression, is contraindicated because of its proconvulsant activity in the infantile form of AxD, which is also characterized by the occurrence of epileptic seizures, two powerful antiepileptic agents, carbamazepine (CBZ) and phenytoin (PHT), which share specific stereochemical features in common with CLM, were taken into consideration in a reliable in vitro model of AxD. In the present work, we document for the first time that CBZ and PHT have a definite inhibitory effect on pathological GFAP cellular expression and folding. Moreover, we confirm previous results of a similar beneficial effect of CLM. In addition, we have demonstrated that CBZ and CLM play a refolding effect on mutant GFAP proteins, likely ascribed at the induction of CRYAB expression, resulting in the decrease of mutant GFAP aggregates formation. As CBZ and PHT are currently approved for use in humans, their documented effects on pathological GFAP cellular expression and folding may indicate a potential therapeutic role as disease-modifying agents of these drugs in the clinical management of AxD, particularly in AxD patients with focal epilepsy with and without secondary generalization
Impact of Nutritional Supplementation on Canine Dermatological Disorders
No full textNutritional supplements, also known as complementary feeds, are products administered with the aim of furnishing health benefits, regardless of nutritional needs. They have been used since ancient times in veterinary dermatology, and a number of studies have focused on investigating the health benefits of some ingredients found in commercially available complementary feed for dogs. The aim of this paper is to review the literature available on the use of nutritional supplementation for the management of canine skin diseases, critically appraising the clinical efficacy of such interventions and summarizing the current state of knowledge. This review highlights how these feeds can be considered useful in the management of dermatological disorders and outlines their beneficial effects in the prevention of dietary deficiencies and treatment of diseases, alone, or in addition to conventional pharmacological therapy. In recent years, nutritional supplements have found increasing potential application in veterinary medicine, and the scientific proofs of their beneficial effects are described in this review
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