Complex network statistics to the design of fire breaks for the control of fire spreading

A computational approach for identifying efficient fuel breaks partitions for the containment of fire incidents in forests is proposed. The approach is based on the complex networks statistics, namely the centrality measures and cellular automata modeling. The efficiency of various centrality statistics, such as betweenness, closeness, Bonacich and eigenvalue centrality to select fuel breaks partitions vs. the random-based distribution is demonstrated. Two examples of increasing complexity are considered: (a) an artificial forest of randomly distributed density of vegetation, and (b) a patch from the area of Vesuvio, National Park of Campania, Italy. Both cases assume flat terrain and single type of vegetation. Simulation results over an ensemble of lattice realizations and runs show that the proposed approach appears very promising as it produces statistically significant better outcomes when compared to the random distribution approach

Body image perception and body composition: assessment of perception inconsistency by a new index

BACKGROUND: A correct perception of the body image, as defined by comparison with actual anthropometric analyses, is crucial to ensure the best possible nutritional status of each individual. Bioimpedance analysis (BIA) represents a leading technique to assess body composition parameters and, in particular, the fat mass. This study examined the self-perception of body image at various levels of adiposity proposing a new index. METHODS: We investigated 487 young Italian adults (mean age of males: 21.9 ± 2.4 years; mean age of females: 21.0 ± 2.2 years). Each subject could choose, on the Contour Drawing Rating Scale, the silhouette that he/she considered most resembling his/her perceived body image as well as his/her ideal body image. On each subject, we performed anthropometric measurements and determined the values of Fat mass and  út with BIA. A new index, FAIFAT (Feel fat status minus Actual fat status Inconsistency), was developed to evaluate possible fat status perception inconsistencies by BIA. RESULTS: Based on ideal and feel body image comparison, women showed higher dissatisfaction than men and preferred slimmer silhouettes. FAIFAT values indicated that the fat status perception was correct in the majority of the examined individuals and only three subjects showed a serious misperception. CONCLUSIONS: Our findings suggest that FAIFAT is an appropriate index for assessing the perceived fat status from the body image when compared with data obtained by BIA. In a population, the use of this index will allow the correct identification of groups at risk for eating disorders

Strong Magnetic Limit of String Theory

We show that there exists a certain limit in type I and type II superstring theory in the presence of a suitable configuration of magnetic U(1) fields where all string excitations get an infinite mass, except for the neutral massless sector and for the boson and fermion string states lying on the leading Regge trajectory. For a supersymmetric configuration of magnetic fields in internal directions, the resulting theory after the limit is a 3+1 Lorentz invariant supersymmetric theory. Supersymmetry can be broken by introducing extra components of the magnetic field or else by finite temperature. In both cases we compute the one-loop partition function for the type I string model after taking the limit, which turns out to be different from the Yang-Mills result that arises by a direct $\alpha'\to 0$ limit. In the case of finite temperature, no Hagedorn transition appears, in consistency with the reduction of the string spectrum. In type II superstring theory, the analogous limit is constructed by starting with a configuration of Melvin twists in two or more complex planes. The resulting theory contains gravitation plus an infinite number of states of the leading Regge trajectory.Comment: 10 pages. Minor correction

Use of phytotherapics in dogs and cats.

Phytotherapy is one of the most utilized non conventional medicines (NCM) both in human and veterinary medicine. It can be used to mitigate and prevent slight diseases and to support conventional medicine using allopathic drugs. In this paper the Authors report the phytoterapeutics most utilized in both dogs and cats, in which the use of phytotherapics is increasing, despite the prejudices of the academic world and of the veterinary practitioners. Laws regarding the use of non conventional medicines in veterinary practises are lacking in Italy, despite many other countries in Europe; yet National Federation of Italian Veterinaries (F.N.O.V.I.) asserted that the use of NCM has to be considered a veterinary practise at all. At the end of this paper, the Authors provided many examples of phytotheapic prescriptions to control different illness in both dogs and cats

Non-Commutative Yang-Mills and the AdS/CFT Correspondence

We study the non-commutative supersymmetric Yang-Mills theory at strong coupling using the AdS/CFT correspondence. The supergravity description and the UV/IR relation confirms the expectation that the non-commutativity affects the ultra-violet but not the infra-red of the Yang-Mills dynamics. We show that the supergravity solution dual to the non-commutative N=4 SYM in four dimensions has no boundary and defines a minimal scale. We also show that the relation between the B field and the scale of non-commutativity is corrected at large coupling and determine its dependence on the 't Hooft coupling \lambda.Comment: 9 pages, 1 figure, References and comments added, typos correcte

Conformal description of horizon's states

The existence of black hole horizon is considered as a boundary condition to be imposed on the fluctuating metrics. The coordinate invariant form of the condition for class of spherically symmetric metrics is formulated. The diffeomorphisms preserving this condition act in (arbitrary small) vicinity of the horizon and form the group of conformal transformations of two-dimensional space ($r-t$ sector of the total space-time). The corresponding algebra recovered at the horizon is one copy of the Virasoro algebra. For general relativity in $d$ dimensions we find an effective two-dimensional theory governing the conformal dynamics at the horizon universally for any $d\geq 3$. The corresponding Virasoro algebra has central charge $c$ proportional to the Bekenstein-Hawking entropy. Identifying the zero-mode configuration we calculate $L_0$. The counting of states of this horizon's conformal field theory by means of Cardy's formula is in complete agreement with the Bekenstein-Hawking expression for the entropy of black hole in $d$ dimensions.Comment: 13 pages, latex, no figures; the final version to appear in Phys. Lett.

The Carbon Monoxide Abundance in Comet 103P/Hartley during the EPOXI Flyby

We report the detection of several emission bands in the CO Fourth Positive Group from comet 103P/Hartley during ultraviolet spectroscopic observations from the Hubble Space Telescope (HST) on 2010 November 4 near the time of closest approach by NASA's EPOXI spacecraft. The derived CO/H2O ratio is 0.15-0.45%, which places 103P among the most CO-depleted comets. Apparently this highly volatile species, whose abundance varies by a factor of ~50 among the comets observed to date, does not play a major role in producing the strong and temporally variable activity in 103P/Hartley. The CO emissions varied by ~30% between our two sets of observations, apparently in phase with the temporal variability measured for several gases and dust by other observers. The low absolute abundance of CO in 103P suggests several possibilities: the nucleus formed in a region of the solar nebula that was depleted in CO or too warm to retain much CO ice, repeated passages through the inner solar system have substantially depleted the comet's primordial CO reservoir, or any CO still in the nucleus is buried below the regions that contribute significantly to the coma.Comment: 14 pages, 3 figures, 2 tables Accepted for publication in Astrophysical Journal Letter

Model of black hole evolution

From the postulate that a black hole can be replaced by a boundary on the apparent horizon with suitable boundary conditions, an unconventional scenario for the evolution emerges. Only an insignificant fraction of energy of order $(mG)^{-1}$ is radiated out. The outgoing wave carries a very small part of the quantum mechanical information of the collapsed body, the bulk of the information remaining in the final stable black hole geometry.Comment: 9 pages, harvmac, 3 figures, minor addition