217 research outputs found
The Paradox of Tik Tok Anti-Pro-Anorexia Videos: How Social Media Can Promote Non-Suicidal Self-Injury and Anorexia
The literature shows that social pressure promotes non-suicidal self-injury (NSSI) eating disorders, along with self-injury, are also favored by underregulated social media. Tik tok is one of the most used social media platforms among adolescents. It has been shown that the time young children spend on this platform doubled during the lockdown. The theme of anorexia is very common on this platform. While most "pro-ana" (pro-anorexia) videos, where users exchanged advice on how to pathologically lose weight, have been censored by the application, other "anti-pro-ana" (anti-pro-anorexia) videos, officially aimed at raising awareness of the consequences of anorexia, have become increasingly popular. However, our case shows how even these safer videos paradoxically lead the users to emulate these "guilty" behaviors
On the phenomenological classification of continuum radio spectra variability patterns of Fermi blazars
The F-GAMMA program is a coordinated effort to investigate the physics of
Active Galactic Nuclei (AGNs) via multi-frequency monitoring of {\em Fermi}
blazars. The current study is concerned with the broad-band radio spectra
composed of measurement at ten frequencies between 2.64 and 142 GHz. It is
shown that any of the 78 sources studied can be classified in terms of their
variability characteristics in merely 5 types of variability. The first four
types are dominated by spectral evolution and can be reproduced by a simple
two-component system made of the quiescent spectrum of a large scale jet
populated with a flaring event evolving according to Marscher & Gear (1985).
The last type is characterized by an achromatic change of the broad-band
spectrum which must be attributed to a completely different mechanism. Here are
presented, the classification, the assumed physical system and the results of
simulations that have been conducted.Comment: 2011 Fermi Symposium proceedings - eConf C11050
On the influence of the Sun on the rapid variability of compact extragalactic sources
Starting from December 2004, a program for the monitoring of intraday
variable sources at a frequency of 5 GHz was performed at the Urumqi
Observatory. The analysis of the variability characteristics of the
flat-spectrum radio source AO 0235+164 revealed the existence of an annual
cycle in the variability amplitude. This appears to correlate with the solar
elongation of the source. A thorough analysis of the results of the MASIV IDV
survey --- which provides the variability characteristics of a large sample of
compact radio sources --- confirms that there is a small but detectable
component of the observed fractional modulation which increases with decreasing
solar elongation. We discuss the hypothesis that the phenomenon is related to
interplanetary scintillation.Comment: 10 pages, 12 figures and 2 tables. Accepted for publication in
Astronomy and Astrophysic
Herschel SPIRE Fourier Transform Spectrometer: Calibration of its Bright-source Mode
The Fourier Transform Spectrometer (FTS) of the Spectral and Photometric
Imaging REceiver (SPIRE) on board the ESA Herschel Space Observatory has two
detector setting modes: (a) a nominal mode, which is optimized for observing
moderately bright to faint astronomical targets, and (b) a bright-source mode
recommended for sources significantly brighter than 500 Jy, within the SPIRE
FTS bandwidth of 446.7-1544 GHz (or 194-671 microns in wavelength), which
employs a reduced detector responsivity and out-of-phase analog signal
amplifier/demodulator. We address in detail the calibration issues unique to
the bright-source mode, describe the integration of the bright-mode data
processing into the existing pipeline for the nominal mode, and show that the
flux calibration accuracy of the bright-source mode is generally within 2% of
that of the nominal mode, and that the bright-source mode is 3 to 4 times less
sensitive than the nominal mode.Comment: 15 pages, 16 figures, accepted for publication in Experimental
Astronom
Radio variability of 1st 3-months Fermi blazars at 5 GHz: affected by interstellar scintillation?
Blazars from the first-three-months Fermi-AGN list were observed with the
Urumqi 25m radio telescope at 5GHz in IDV (Intra-Day Variability) mode and
inter-month observation mode. A significant correlation between the flux
density at 5GHz and the gamma-ray intensity for the Fermi-LAT detected blazars
is seen. There is a higher IDV detection rate in Fermi detected blazars than
those reported for other samples. Stronger variability appears at lower
Galactic latitudes; IDV appears to be stronger in weaker sources, indicating
that the variability is affected by interstellar scintillation.Comment: 4 pages, 4 figures, in proceedings of 'Multiwavelength Variability of
Blazars' in Guangzhou Uni. of China, 22-24, Sep. 2010, to appear in JA
F-GAMMA: On the phenomenological classification of continuum radio spectra variability patterns of Fermi blazars
The F-GAMMA program is a coordinated effort to investigate the physics of
Active Galactic Nuclei (AGNs) via multi-frequency monitoring of Fermi blazars.
In the current study we show and discuss the evolution of broad-band radio
spectra, which are measured at ten frequencies between 2.64 and 142 GHz using
the Effelsberg 100-m and the IRAM 30-m telescopes. It is shown that any of the
78 sources studied can be classified in terms of their variability
characteristics in merely 5 types of variability. It is argued that these can
be attributed to only two classes of variability mechanisms. The first four
types are dominated by spectral evolution and can be described by a simple
two-component system composed of: (a) a steep quiescent spectral component from
a large scale jet and (b) a time evolving flare component following the
"Shock-in-Jet" evolutionary path. The fifth type is characterised by an
achromatic change of the broad band spectrum, which could be attributed to a
different mechanism, likely involving differential Doppler boosting caused by
geometrical effects. Here we present the classification, the assumed physical
scenario and the results of calculations that have been performed for the
spectral evolution of flares.Comment: Proceedings of the conference: "The Central Kiloparsec in Galactic
Nucleic: Astronomy at High Angular Resolution 2011", August 29 - September 2,
2011, Bad Honnef, German
Epidermolysis Bullosa in children: the central role of the pediatrician
Epidermolysis bullosa (EB) is a severe hereditary disease characterized by defective epithelial adhesion causing mucocutaneous fragility. The major types are EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB) and more than 35 EB subtypes. Another very rare type of EB is Kindler EB (KEB). Clinically, it is a very heterogeneous disease which ranges from localized to extensive skin lesions with frequent multisystem extra cutaneous involvement. The role of a pediatrician-dermatologist cooperation within a multidisciplinary team is fundamental for both the diagnosis and management contributing to these patients' better life expectancy. Aim of this study is to describe clinical and laboratory characteristics of the main EB subtypes focusing on nutritional and gastrointestinal aspects, providing information to aid the paediatric management of children with EB. This retrospective study reviewed the cases of 160 pediatric EB patients (76 male and 84 female): 31 patients affected by EBS (mean age +/- SD: 4.37 +/- 7.14), 21 patients affected by JEB (mean age +/- SD: 9.26 +/- 17.30) and 108 with DEB (mean age +/- SD: 11.61 +/- 13.48). All patients were admitted at the Bambino Gesu Children's Hospital in Rome, between June 2005 to June 2020. The reduced gastrointestinal absorption, chronic losses, esophageal stenosis and chronic inflammatory state, represent the basis of nutritional problems of EB patients. In particular, anemia represents one of the most important complications of DEB patients which could require transfusion-dependent patterns. Malnutrition, vitamin deficiencies and anemia have been related to growth delay in EB patients. A specific diet with a balance of all macronutrients is required and improving caloric intake with sugar limitations is fundamental to prevent dental caries and tooth decay typical of EB patients. While sepsis proved to be the major cause of morbidity and mortality in younger patients, squamous cell carcinoma was mostly observed in older patients, especially those affected by DEB. Patients with EB require regular monitoring for complications and sequelae with a frequency of evaluations which varies based on age and EB subtypes. Cooperation among medical teams involving paediatricians, dermatologists, specialist clinicians including nutritionists such as families and patient's association is fundamental to approach the disease and improve the quality of life of these patients
Accidental Nasal Myiasis Caused by Megaselia rufipes (Diptera: Phoridae) in a Child
A case of a nasal myiasis in a 3-yr-old Italian girl who was referred to Bambino GesĂą Hospital in Rome, Italy, is reported. Larvae discharged with the nasal mucus were microscopically identified as Megaselia spp.; DNA barcoding analysis showed that they belonged to the 'scuttle fly' species Megaselia rufipes (Meigen). Based on the patient's history, she became infected when she played outside. This is the first report of myiasis in humans due to M. rufipes (Diptera: Phoridae)
Calibration of <i>Herschel</i> SPIRE FTS observations at different spectral resolutions
The SPIRE Fourier Transform Spectrometer on-board the Herschel Space Observatory had two standard spectral resolution modes for science observations: high resolution (HR) and low resolution (LR), which could also be performed in sequence (H+LR). A comparison of the HR and LR resolution spectra taken in this sequential mode revealed a systematic discrepancy in the continuum level. Analysing the data at different stages during standard pipeline processing demonstrates that the telescope and instrument emission affect HR and H+LR observations in a systematically different way. The origin of this difference is found to lie in the variation of both the telescope and instrument response functions, while it is triggered by fast variation of the instrument temperatures. As it is not possible to trace the evolution of the response functions using housekeeping data from the instrument subsystems, the calibration cannot be corrected analytically. Therefore, an empirical correction for LR spectra has been developed, which removes the systematic noise introduced by the variation of the response functions
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