2,556 research outputs found
Using Technology to Enhance Pre-Service Teacher Preparation
Use of the internet to deliver a portion of the content in an introductory science, education, and technology methods course for pre-service teachers provides an opportunity for a much needed introduction to basic computer literacy. A web page was developed for use in conjunction with the math, science, and technology educational methods courses at Brooklyn College. Students are introduced to this page as a group in the computer lab, and work in small groups with more experienced students serving as mentors to other students. The Brooklyn College Science Education Webpage is designed as a simple jump page with links to various resources for science education. It serves as a starting point to expose pre-service teachers to a wide range of resources available to them on the world wide web and in the real world. Students use their internet research skills in open-ended assignments throughout the semester. The web page continues to serve as a resource for students in the next courses in the math and science education sequence. The Brooklyn College Science Education Webpage helps education graduates to begin their teaching better prepared to use technology in the classroom
Secondary radiation from the Pamela/ATIC excess and relevance for Fermi
The excess of electrons/positrons observed by the Pamela and ATIC experiments
gives rise to a noticeable amount of synchrotron and Inverse Compton Scattering
(ICS) radiation when the e^+e^- interact with the Galactic Magnetic Field, and
the InterStellar Radiation Field (ISRF). In particular, the ICS signal produced
within the WIMP annihilation interpretation of the Pamela/ATIC excess shows
already some tension with the EGRET data. On the other hand, 1 yr of Fermi data
taking will be enough to rule out or confirm this scenario with a high
confidence level. The ICS radiation produces a peculiar and clean "ICS Haze"
feature, as well, which can be used to discriminate between the astrophysical
and Dark Matter scenarios. This ICS signature is very prominent even several
degrees away from the galactic center, and it is thus a very robust prediction
with respect to the choice of the DM profile and the uncertainties in the ISRF.Comment: 5 pages, 3 figures; v2: improved figures, enlarged discussion on the
gamma signal and data; to appear in ApJ
Ultrahigh energy neutrinos with a mediterranean neutrino telescope
A study of the ultra high energy neutrino detection performances of a km^3
Neutrino Telescope sitting at the three proposed sites for "ANTARES", "NEMO"
and "NESTOR" in the Mediterranean sea is here performed. The detected charged
leptons energy spectra, entangled with their arrival directions, provide an
unique tool to both determine the neutrino flux and the neutrino-nucleon cross
section.Comment: 10 pages, 10 figures, Proceedings of XII International Workshop on
Neutrino Telescopes, Venezia 200
Gradient methods in control theory. Part 2 - Sequential gradient-restoration algorithm
Sequential gradient-restoration algorith
Radio constraints on dark matter annihilation in the galactic halo and its substructures
Annihilation of Dark Matter usually produces together with gamma rays
comparable amounts of electrons and positrons. The e+e- gyrating in the
galactic magnetic field then produce secondary synchrotron radiation which thus
provides an indirect mean to constrain the DM signal itself. To this purpose,
we calculate the radio emission from the galactic halo as well as from its
expected substructures and we then compare it with the measured diffuse radio
background. We employ a multi-frequency approach using data in the relevant
frequency range 100 MHz-100 GHz, as well as the WMAP Haze data at 23 GHz. The
derived constraints are of the order =10^{-24} cm3 s^{-1} for a DM
mass m_chi=100 GeV sensibly depending however on the astrophysical
uncertainties, in particular on the assumption on the galactic magnetic field
model. The signal from single bright clumps is instead largely attenuated by
diffusion effects and offers only poor detection perspectives.Comment: 12 pages, 7 figures; v2: some references added, some discussions
enlarged; matches journal versio
Identification of a specific region of low molecular weight phospholipases A2 (residues 21-40) as a potential target for structure-based design of inhibitors of these enzymes.
High Energy Neutrinos with a Mediterranean Neutrino Telescope
The high energy neutrino detection by a km^3 Neutrino Telescope placed in the
Mediterranean sea provides a unique tool to both determine the diffuse
astrophysical neutrino flux and the neutrino-nucleon cross section in the
extreme kinematical region, which could unveil the presence of new physics.
Here is performed a brief analysis of possible NEMO site performances.Comment: 4 pages, 3 figures, Proceedings of the 30th ICRC 200
Disentangling neutrino-nucleon cross section and high energy neutrino flux with a km^3 neutrino telescope
The energy--zenith angular event distribution in a neutrino telescope
provides a unique tool to determine at the same time the neutrino-nucleon cross
section at extreme kinematical regions, and the high energy neutrino flux. By
using a simple parametrization for fluxes and cross sections, we present a
sensitivity analysis for the case of a km^3 neutrino telescope. In particular,
we consider the specific case of an under-water Mediterranean telescope placed
at the NEMO site, although most of our results also apply to an under-ice
detector such as IceCube. We determine the sensitivity to departures from
standard values of the cross sections above 1 PeV which can be probed
independently from an a-priori knowledge of the normalization and energy
dependence of the flux. We also stress that the capability to tag downgoing
neutrino showers in the PeV range against the cosmic ray induced background of
penetrating muons appears to be a crucial requirement to derive meaningful
constraints on the cross section.Comment: 10 pages, 28 figure
Space-time symmetry restoration in cosmological models with Kalb--Ramond and scalar fields
We study symmetry of space-time in presence of a minimally coupled scalar
field interacting with a Kalb--Ramond tensor fields in a homogeneous but
initially anisotropic universe. The analysis is performed for the two relevant
cases of a pure cosmological constant and a minimal quadratic, renormalizable,
interaction term. In both cases, due to expansion, a complete spatial symmetry
restoration is dynamically obtained.Comment: Latex, 7 pages, 3 eps figure
The Scalar wave equation in a non-commutative spherically symmetric space-time
Recent work in the literature has studied a version of non-commutative Schwarzschild
black holes where the effects of non-commutativity are described by a mass function
depending on both the radial variable r and a non-commutativity parameter θ. The
present paper studies the asymptotic behavior of solutions of the zero-rest-mass scalar
wave equation in such a modified Schwarzschild space-time in a neighborhood of spatial
infinity. The analysis is eventually reduced to finding solutions of an inhomogeneous
Euler–Poisson–Darboux equation, where the parameter θ affects explicitly the functional
form of the source term. Interestingly, for finite values of θ, there is full qualitative
agreement with general relativity: the conformal singularity at spacelike infinity reduces
in a considerable way the differentiability class of scalar fields at future null infinity.
In the physical space-time, this means that the scalar field has an asymptotic behavior
with a fall-off going on rather more slowly than in flat space-time
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