5,288 research outputs found
DNA waves and water
Some bacterial and viral DNA sequences have been found to induce low
frequency electromagnetic waves in high aqueous dilutions. This phenomenon
appears to be triggered by the ambient electromagnetic background of very low
frequency. We discuss this phenomenon in the framework of quantum field theory.
A scheme able to account for the observations is proposed. The reported
phenomenon could allow to develop highly sensitive detection systems for
chronic bacterial and viral infections.Comment: Invited talk at the DICE2010 Conference, Castiglioncello, Italy
September 201
How heavy can the Fermions in Split Susy be? A study on Gravitino and Extradimensional LSP
In recently introduced Split Susy theories, in which the scale of Susy
breaking is very high, the requirement that the relic abundance of the Lightest
SuperPartner (LSP) provides the Dark Matter of the Universe leads to the
prediction of fermionic superpartners around the weak scale. This is no longer
obviously the case if the LSP is a hidden sector field, such as a Gravitino or
an other hidden sector fermion, so, it is interesting to study this scenario.
We consider the case in which the Next-Lightest SuperPartner (NLSP) freezes out
with its thermal relic abundance, and then it decays to the LSP. We use the
constraints from BBN and CMB, together with the requirement of attaining Gauge
Coupling Unification and that the LSP abundance provides the Dark Matter of the
Universe, to infer the allowed superpartner spectrum. As very good news for a
possible detaction of Split Susy at LHC, we find that if the Gravitino is the
LSP, than the only allowed NLSP has to be very purely photino like. In this
case, a photino from 700 GeV to 5 TeV is allowed, which is difficult to test at
LHC. We also study the case where the LSP is given by a light fermion in the
hidden sector which is naturally present in Susy breaking in Extra Dimensions.
We find that, in this case, a generic NLSP is allowed to be in the range 1-20
TeV, while a Bino NLSP can be as light as tens of GeV.Comment: 29 pages, 12 figures. v2: modified conclusions for bino NLSP. v3:
corrected small mistake in Gauge Coupling Unification, conclusions unchange
Counting dark matter particles in LHC events
We suggest trying to count the number of invisible particles produced in
missing energy events at the LHC, arguing that multiple production of such
particles provides evidence that they constitute stable Dark Matter and that
counting them could yield further insights into the nature of Dark Matter. We
propose a method to count invisible particles, based on fitting the shapes of
certain transverse- or invariant-mass distributions, discuss various effects
that may affect the measurement, and simulate the use of the method to count
neutrinos in Standard Model processes and Dark Matter candidates in new physics
processes.Comment: 18 pages, 13 figures, revtex4 forma
Why the Water Bridge does not collapse
In 2007 an interesting phenomenon was discovered: a thread of water, the
so-called water bridge (WB), can hang between two glass beakers filled with
deionized water if voltage is applied to them. We analyze the available
explanations of the WB stability and propose a completely different one: the
force that supports the WB is the surface tension of water and the role of
electric field is not to allow the WB to reduce its surface energy by means of
breaking into separate drops.Comment: 4 pages, 3 figure
Guideline on management of the acute asthma attack in children by Italian Society of Pediatrics.
BACKGROUND: Acute asthma attack is a frequent condition in children. It is one of the most common reasons for emergency department (ED) visit and hospitalization. Appropriate care is fundamental, considering both the high prevalence of asthma in children, and its life-threatening risks. Italian Society of Pediatrics recently issued a guideline on the management of acute asthma attack in children over age 2, in ambulatory and emergency department settings. METHODS: The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was adopted. A literature search was performed using the Cochrane Library and Medline/PubMed databases, retrieving studies in English or Italian and including children over age 2 year. RESULTS: Inhaled ß2 agonists are the first line drugs for acute asthma attack in children. Ipratropium bromide should be added in moderate/severe attacks. Early use of systemic steroids is associated with reduced risk of ED visits and hospitalization. High doses of inhaled steroids should not replace systemic steroids. Aminophylline use should be avoided in mild/moderate attacks. Weak evidence supports its use in life-threatening attacks. Epinephrine should not be used in the treatment of acute asthma for its lower cost / benefit ratio, compared to β2 agonists. Intravenous magnesium solphate could be used in children with severe attacks and/or forced expiratory volume1 (FEV1) lower than 60% predicted, unresponsive to initial inhaled therapy. Heliox could be administered in life-threatening attacks. Leukotriene receptor antagonists are not recommended. CONCLUSIONS: This Guideline is expected to be a useful resource in managing acute asthma attacks in children over age 2
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