2,414 research outputs found
Can LSND and SuperKamiokande be explained by radiative decays of muons-neutrinos?
The radiative decay of muon-neutrinos in matter with a scheme of
mass-degenerate neutrinos could be the common origin of the appearance of
anti-electron-neutrinos at LSND and the disappearance of muons-neutrinos at
SuperKamiokande. With the decay probability fixed by the LSND signal, the
deficit of atmospheric neutrinos can be satisfactorily reproduced.Comment: 4 pages, 0 figur
Search for Stimulated Neutrino Conversion with an RF Cavity
Little is known on radiative decays of numu and nutau. Lifetimes can be
constrained, or the process discovered, by a search for flavour conversion in a
superconducting RF cavity installed in a neutrino beam. The lifetimes tested
with such a method can be of interest for astrophysics and cosmology. In
particular the conjecture which explains both the LSND and the SuperKamiokande
signals by radiative decays of numu can be straightforwardly put to the test.Comment: 4 pages, 1 figure, contributed paper to the "Rencontres de Blois",
Blois, France, June 28 - July 3 199
Detecting cosmic rays of the highest energies
Charged cosmic rays have been measured up to macroscopic energies. Concerning
neutrinos, the detection is still limited to terrestrial ones (apart from
supernova production). A new way to search for extragalactic neutrinos is
discussed.Comment: 5 pages, NATO Advanced research Workshop, Morocco, March 200
A consistent interpretation of the Karmen anomaly
The Karmen anomaly can be interpreted as being due to a heavy neutrino of
mass around 137 MeV produced in decays. This interpretation is
consistent with the present limits on the couplings of such an object.Comment: 11pages, 4figures, Te
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Screening for developmental disorders in 3- and 4-year-old italian children: a preliminary study
BACKGROUND:
The "Osserviamo" project, coordinated by the Municipality of Rome and the Department of Pediatrics and Child Neuropsychiatry of Sapienza University, aimed to validate an Italian version of the Ages and Stages Questionnaire-3 and to collect, for the first time in Italy, data on developmental disorders in a sample of 4,000 children aged 3 and 4 years. The present paper presents the preliminary results of the "Osserviamo" project.
METHODS:
600 parents of children between 39 and 50 months of age (divided in two age stages: 42 and 48 months) were contacted from 15 kindergarden schools.
RESULTS:
23.35% of the whole sample scored in the risk range of at least one developmental area of the Ages and Stages Questionnaire-3rd Edition (ASQ-3) and 7.78% scored in the clinical range. Specifically, 23.97% of the children in the 42-month age stage scored in the risk range and 5.79% scored in the clinical range. Males scored lower than females in the fine motor skills and personal-social development domains. Moreover, 22.79% of the children in the 48-month age stage scored in the risk range, while 9.55% scored in the clinical range. Males scored lower than females in fine motor skills.
CONCLUSION:
Italian validation of the ASQ-3 and recruitment of all 4,000 participants will allow these data on the distribution of developmental disorders to be extended to the general Italian pediatric population. One main limitation of the study is the lack of clinical confirmation of the data yielded by the screening programme, which the authors aim to obtain in later stages of the study
Autoclavable addition polyimides for 371 C composite applications
Studies were conducted to improve the thermo-oxidative stability (TOS) of PMR type polyimides by the substitution of para-aminostyrene (PAS) for the nadic ester endcap in second generation PMR polyimides (PMR-2). The nadic endcap which provides the PMR polyimides with their relative ease of fabrication, both by limiting the molecular weight of the prepolymer and by undergoing the final addition cure without volatiles, is also the weak link with regard to TOS. A polyimide formulated with PAS endcaps, called V-CAP, utilizes a two step reaction sequence similar to that of the PMR polyimides and can be easily autoclave molded into low void composite materials. Resin studies included two formulations of both PMR-2 and V-CAP, corresponding to n=9 and n=14 prepolymer stoichiometry. Unidirectional reinforced T40R graphite fiber laminates were fabricated from each of the resins was post-cured in either air at 385 C or nitrogen at 400 C. Composite specimens were aged in air at 371 C and mechanical properties were measured at 371 C before and after exposure
Diagnosis and endovascular treatment of an internal mammary artery injury
Internal mammary artery (IMA) disruption after blunt chest trauma is rare. In some instances, it may occur after
mild chest trauma with minor external physical findings. However, prompt diagnosis and treatment are necessary,
as it can be associated with vascular and parenchymal injuries.
We report a case of blunt chest trauma resulting in a sternal fracture associated with an IMA injury, active
anterior mediastinal bleeding, bilateral lung contusions, and a left hemothorax. It was successfully treated by selective
embolization to the left IMA branch and chest tube placement
Mediastinitis and sternal prosthesis infection successfully treated by minimally invasive omental flap transposition
Purulent mediastinitis is a possible serious complication after mediastinal surgery. We report the case of a localized
sternal plasmocytoma treated by sternectomy and prosthetic repair, who needed a second surgery for a fistulizing
mediastinitis. Five months earlier, in another Hospital, the patient underwent sternal resection and reconstruction
with a “sandwich” prosthesis (Methyl-methacrylate and Marlex mesh). Suppurative mediastinitis occurred and septic
shock resolution was observed after the spontaneous opening of a mediastinal cutaneous fistula. After referring to
our Unit the patient underwent extensive local and systemic preparation and nutritional support; the infected
prosthesis was then removed and the gap filled by a laparoscopically-prepared omental flap. Adequate
preoperative management, removal of any infected material and minimally invasive omental flap transposition
allowed the successful treatment of this life-threatening condition
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