4,299 research outputs found
Coarse Grained Liouville Dynamics of piecewise linear discontinuous maps
We compute the spectrum of the classical and quantum mechanical
coarse-grained propagators for a piecewise linear discontinuous map. We analyze
the quantum - classical correspondence and the evolution of the spectrum with
increasing resolution. Our results are compared to the ones obtained for a
mixed system.Comment: 11 pages, 8 figure
Mandatory vaccinations in European countries, undocumented information, false news and the impact on vaccination uptake: the position of the Italian pediatric society.
BACKGROUND: High rates of vaccination coverage are important in preventing infectious diseases. Enforcing mandatory vaccinations is one of the strategies that some Countries adopted to protect the community when vaccination coverage is not satisfactory. In Italy, in 2017 vaccination against diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella became compulsory in childhood. In order to contrast vaccination policies, anti-vaccination campaigns contribute to the spread of fake news. Among them, there is the false information that Italy is the only one country with mandatory vaccination policy. Aim of our study is confronting vaccination policies in children under 18 months against among different European countries for the following vaccines: diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella. METHODS: Information on policies of mandatory or recommended vaccinations of the European Countries were gathered by ECDC and compared to the Italian one. RESULTS: European Countries recommend or contemplate compulsory vaccines. Among them, eleven Countries (35.4%) have mandatory vaccinations for at least one out of diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella vaccine. CONCLUSION: Not only in Italy, vaccination against diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella is mandatory in children under 18 months. Other European countries adopted compulsory policies in order to prevent the spread of infectious diseases and to protect the community
Media devices in pre-school children: the recommendations of the Italian pediatric society
BACKGROUND: Young children are too often exposed to mobile devices (MD) and most of them had their own device. The adverse effects of a early and prolonged exposure to digital technology on pre-school children has been described by several studies. Aim of the study is to analyze the consequences of MD exposure in pre-school children. METHODS: We analyzed the documented effects of media exposure on children's mental and physical health. RESULTS: According to recent studies, MD may interfere with learning, children development, well being, sleep, sight, listening, caregiver-child relationship. DISCUSSION: Pediatricians should be aware of both the beneficial and side effects of MD and give advice to the families, according to children's age. CONCLUSION: In according to literature, the Italian Pediatric Society suggest that the media device exposure in childhood should be modulated by supervisors
Knee Arthrodesis with the Ilizarov External Fixator as Treatment for Septic Failure of Knee Arthroplasty
Optically switched magnetism in photovoltaic perovskite CHNH(Mn:Pb)I
The demand for ever-increasing density of information storage and speed of
manipulation boosts an intense search for new magnetic materials and novel ways
of controlling the magnetic bit. Here, we report the synthesis of a
ferromagnetic photovoltaic CHNH(Mn:Pb)I material in which the
photo-excited electrons rapidly melt the local magnetic order through the
Ruderman-Kittel-Kasuya-Yosida interactions without heating up the spin system.
Our finding offers an alternative, very simple and efficient way of optical
spin control, and opens an avenue for applications in low power, light
controlling magnetic devices
The Solar Twin Planet Search II. A Jupiter twin around a solar twin
Through our HARPS radial velocity survey for planets around solar twin stars,
we have identified a promising Jupiter twin candidate around the star HIP11915.
We characterize this Keplerian signal and investigate its potential origins in
stellar activity. Our analysis indicates that HIP11915 hosts a Jupiter-mass
planet with a 3800-day orbital period and low eccentricity. Although we cannot
definitively rule out an activity cycle interpretation, we find that a planet
interpretation is more likely based on a joint analysis of RV and activity
index data. The challenges of long-period radial velocity signals addressed in
this paper are critical for the ongoing discovery of Jupiter-like exoplanets.
If planetary in nature, the signal investigated here represents a very close
analog to the solar system in terms of both Sun-like host star and Jupiter-like
planet.Comment: 8 pages, 5 figures; A&A accepted; typos corrected in this versio
Media use during adolescence: the recommendations of the Italian Pediatric Society.
BACKGROUND: The use of media device, such as smartphone and tablet, is currently increasing, especially among the youngest. Adolescents spend more and more time with their smartphones consulting social media, mainly Facebook, Instagram and Twitter because. Adolescents often feel the necessity to use a media device as a means to construct a social identity and express themselves. For some children, smartphone ownership starts even sooner as young as 7 yrs, according to internet safety experts. MATERIAL AND METHODS: We analyzed the evidence on media use and its consequences in adolescence. RESULTS: In literature, smartphones and tablets use may negatively influences the psychophysical development of the adolescent, such as learning, sleep and sigh. Moreover, obesity, distraction, addiction, cyberbullism and Hikikomori phenomena are described in adolescents who use media device too frequently. The Italian Pediatric Society provide action-oriented recommendations for families and clinicians to avoid negative outcomes. CONCLUSIONS: Both parents and clinicians should be aware of the widespread phenomenon of media device use among adolescents and try to avoid psychophysical consequences on the youngest
Correction: Diagnosis of carotid and vertebral artery injury in major trauma with head injury
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