The extended conformal theory of Luttinger systems

We describe the recently introduced method of algebraic bosonization of the $(1+1)$-dimensional Luttinger systems by discussing in detail the specific case of the Calogero-Sutherland model, and mentioning the hard-core Bose gas. We also compare our findings with the exact Bethe Ansatz results.Comment: 9 pages, plain Latex file, ,based on a talk given by S. Sciuto at the II International Sakharov Conference on Physics, Moscow, Russia, 20-24 May 9

The extended conformal theory of the Calogero-Sutherland model

We describe the recently introduced method of Algebraic Bosonization of (1+1)-dimensional fermionic systems by discussing the specific case of the Calogero-Sutherland model. A comparison with the Bethe Ansatz results is also presented.Comment: 12 pages, plain LaTeX, no figures; To appear in the proceedings of the IV Meeting "Common Trends in Condensed Matter and High Energy Physics", Chia Laguna, Cagliari, Italy, 3-10 Sep. 199

Nuclear Localization of the Functional Bel 1 Transactivator but Not of the Gag Proteins of the Feline Foamy Virus

AbstractInteractions between host cells and foamy or spumaretroviruses are different from those of other known retroviruses. Previous work has suggested that the Gag and high-affinity DNA-binding Bel 1 transactivator of human foamy virus are localized in the nuclei of infected cells. Using two independent detection methods, we show here that the functionally active Bel 1 transactivator protein of feline foamy virus is of nuclear localization. In contrast to that reported for the human foamy virus Gag protein, the cat foamy virus Gag proteins exclusively localized in the cytoplasm close to perinuclear regions

Effective Field Theories for Electrons in Crystalline Structures

We present an effective field theory formulation for a class of condensed matter systems with crystalline structures for which some of the discrete symmetries of the underlying crystal survive the long distance limit, up to mesoscopic scales, and argue that this class includes interesting materials, such as $Si$-doped $GaAs$. The surviving symmetries determine a limited set of possible effective interactions, that we analyze in detail for the case of $Si$-doped $GaAs$ materials. These coincide with the ones proposed in the literature to describe the spin relaxation times for the $Si$-doped $Ga As$ materials, obtained here as a consequence of the choice of effective fields and their symmetries. The resulting low-energy effective theory is described in terms of three (six chiral) one-dimensional Luttinger liquid systems and their corresponding intervalley transitions. We also discuss the Mott transition within the context of the effective theory.Comment: 24 pages, 3 figure

Thermodynamics of a model for RNA folding

We analyze the thermodynamic properties of a simplified model for folded RNA molecules recently studied by G. Vernizzi, H. Orland, A. Zee (in {\it Phys. Rev. Lett.} {\bf 94} (2005) 168103). The model consists of a chain of one-flavor base molecules with a flexible backbone and all possible pairing interactions equally allowed. The spatial pseudoknot structure of the model can be efficiently studied by introducing a $N \times N$ hermitian random matrix model at each chain site, and associating Feynman diagrams of these models to spatial configurations of the molecules. We obtain an exact expression for the topological expansion of the partition function of the system. We calculate exact and asymptotic expressions for the free energy, specific heat, entanglement and chemical potential and study their behavior as a function of temperature. Our results are consistent with the interpretation of $1/N$ as being a measure of the concentration of $\rm{Mg}^{++}$ in solution.Comment: 11 pages, 4 figure

Two Years of Simultaneous K(sub a)-Band Measurements: Goldstone, CA; White Sands, NM; and Guam, USA

In order to statistically characterize the effect of the Earth's atmosphere on Ka-Band links, site test interferometers (STIs) have been deployed at three of NASA s operational sites to directly measure each site's tropospheric phase stability and rain attenuation. These STIs are composed of two antennas on a short baseline (less than 1km) that observe the same unmodulated beacon signal broadcast from a geostationary satellite (e.g., Anik F2). The STIs are used to measure the differential phase between the two received signals as well as the individual signal attenuation at each terminal. There are currently three NASA sites utilizing STIs; the Goldstone Deep Space Communications Complex near Barstow, California; the White Sands Complex in Las Cruces, New Mexico; and the Guam Remote Ground Terminal on the island of Guam. The first two sites are both located in desert regions that have highly similar climates in terms of their seasonal temperatures, average humidity, and annual rain fall (the primary factors in determining phase stability). In contrast, Guam is in a tropical region with drastically higher annual rainfall and humidity. Five station years of data have been collected in Goldstone, three in White Sands, and two in Guam, yielding two years of simultaneous data collection across all three sites. During this period of simultaneous data collection, the root-mean-square (RMS) of the time delay fluctuations stayed under 2.40 picoseconds for 90% of the time in Goldstone, under 2.07 picoseconds for 90% of the time in White Sands, and under 10.13 picoseconds for 90% of the time in Guam. For the 99th percentile, the statistics were 6.32 ps, 6.03 ps, and 24.85 ps, respectively. These values, as well as various other site quality characteristics, will be used to determine the suitability of these sites for NASA s future communication services at Ka-Band

Two Years of Site Diversity Measurements in Guam, USA

As NASA communication networks upgrade to higher frequencies, such as Ka-Band, atmospherically induced attenuation can become significant. This attenuation is caused by rain, clouds and atmospheric gases (oxygen and water vapor), with rain having the most noticeable effects. One technique to circumvent the increase in attenuation is to operate two terminals separated by a distance that exceeds the average rain cell size. The fact that rain cells are of finite size can then be exploited by rerouting the signal to the terminal with the strongest link. This technique, known as site diversity, is best suited for climates that have compact (less than 2km) and intense rain cells such as in Guam. In order to study the potential diversity gain at the Tracking and Data Relay Satellite (TDRS) Remote Ground Terminal (GRGT) complex in Guam a site test interferometer (STI) was installed in May of 2010. The STI is composed of two terminals with a 900m baseline that observe the same unmodulated beacon signal broadcast from a geostationary satellite (e.g., UFO 8). The potential site diversity gain is calculated by measuring the difference in signal attenuation seen at each terminal. Over the two years of data collection the cumulative distribution function (CDF) of the site diversity gain shows a better than 3 dB improvement for 90% of the time over standard operation. These results show that the use of site diversity in Guam can be very effective in combating rain fades

Analysis of Environmental and Economic Effects of Kiri Dam, Adamawa State, Nigeria

This research was an attempt to study the consequences of dam construction in Nigeria This was expedient because such projects are known to be characterised by array of disasters that ensued their construction Satellite images captured before and after the dam in 1976 and 2014 respectively were subjected to image processing techniques so as to assess the likely changes in environmental variables of the area This was supplemented by 250 questionnaires administered in settlements along the riverbank to elicit information on the socioeconomic characteristics of the people Additionally field observations and informal interviews were conducted to probe further into details of information required Results show that natural vegetation has decreased by 63 This has led to chains of environmental problems including soil erosion loss of biodiversity and pollution The other land use cover types experienced increase with water body accounting for the highest value of 54 7 owing to dam in the reservoir The hitherto common crops of the area such as maize guinea corn have been replaced with cash crops like cotton and potato etc some of which are foreign to the area This coupled with inundation of farmlands by dam water has constituted undesirable impacts on the livelihood of the local farmers Unfortunately the dam water meant for irrigation farming and fishing has not been utilized maximally Instead the presence of the water has led to emergence of lifethreatening animals and birds It was recommended that the local farmers be provided with appropriate fishing and irrigation facilities to enable them take advantage of the dam Vast hectares of lands lying fallowed should be utilized to ensure food securit

Analysis of Environmental and Economic Effects of Kiri Dam, Adamawa State, Nigeria

This research was an attempt to study the consequences of dam construction in Nigeria This was expedient because such projects are known to be characterised by array of disasters that ensued their construction Satellite images captured before and after the dam in 1976 and 2014 respectively were subjected to image processing techniques so as to assess the likely changes in environmental variables of the area This was supplemented by 250 questionnaires administered in settlements along the riverbank to elicit information on the socioeconomic characteristics of the people Additionally field observations and informal interviews were conducted to probe further into details of information required Results show that natural vegetation has decreased by 63 This has led to chains of environmental problems including soil erosion loss of biodiversity and pollution The other land use cover types experienced increase with water body accounting for the highest value of 54 7 owing to dam in the reservoir The hitherto common crops of the area such as maize guinea corn have been replaced with cash crops like cotton and potato etc some of which are foreign to the area This coupled with inundation of farmlands by dam water has constituted undesirable impacts on the livelihood of the local farmers Unfortunately the dam water meant for irrigation farming and fishing has not been utilized maximally Instead the presence of the water has led to emergence of lifethreatening animals and birds It was recommended that the local farmers be provided with appropriate fishing and irrigation facilities to enable them take advantage of the dam Vast hectares of lands lying fallowed should be utilized to ensure food securit