Exit from inflation and a paradigm for vanishing cosmological constant in self-tuning models

We propose a paradigm for the inflation and the vanishing cosmological constant in a unified way with the self-tuning solutions of the cosmological constant problem. Here, we consider a time-varying cosmological constant in self-tuning models of the cosmological constant. As a specific example, we demonstrate it with a 3-form field in 5D.Comment: 11 pages of LaTeX fil

Biodegradable polymeric prodrugs of naltrexone

The development of a biodegradable polymeric drug delivery system for the narcotic antagonist naltrexone may improve patient compliance in the treatment of opiate addiction. Random copolymers consisting of the ¿-amino acids N5-(3-hydroxypropyl--glutamine and -leucine were synthesized with equimolar initial monomer feeds. The molecular weight of this chemical carrier was determined by viscometry and wide-angle light scattering. In order to get selective covalent coupling of drug to polymer the 3-acetate derivative and the 14-acetate derivative of naltrexone were synthesized and characterized by NMR. Hydrolytic conversion of each monoacetate to parent drug was monitored by HPLC and the rate constant was determined. Both derivatives were coupled via hydrolytically labile carbonate linkages to the polymer hydroxyl groups. The drug conjugates were prepared as particles of various size ranges between 20 and 350 ¿. In vitro studies in phosphate-buffered saline (pH 7.4) demonstrated a release rate dependence on particle size. Nearly constant plasma levels of naltrexone were obtained for one month after subcutaneous injection in rats

Nucleon Spin Structures from Lattice QCD: Flavor Singlet Axial and Tensor Charges

The flavor singlet axial and tensor charges of the nucleon are calculated in lattice QCD. We find $\Delta\Sigma=\Delta u+\Delta d+\Delta s=+0.638(54)-0.347(46)-0.109(30) = +0.18(10)$ for the axial charge and $\delta\Sigma=\delta u+\delta d+\delta s=+0.839(60)-0.231(55)-0.046(34) = +0.562(88)$ for the tensor charge. The result for the axial charge shows reasonable agreement with the experiment and that for the tensor charge is the first prediction from lattice QCD before experimental measurements.Comment: 10 pages, latex source-file, 5 figures as epsf-file, uses espcrc1.sty. Invited talk at the International Conference on Quark Lepton Nuclear Physics, 20-23 May 1997, Osaka, Japa

Taste symmetry breaking with HYP-smeared staggered fermions

We study the impact of hypercubic (HYP) smearing on the size of taste breaking for staggered fermions, comparing to unimproved and to asqtad-improved staggered fermions. As in previous studies, we find a substantial reduction in taste-breaking compared to unimproved staggered fermions (by a factor of 4-7 on lattices with spacing $a\approx 0.1$fm). In addition, we observe that discretization effects of next-to-leading order in the chiral expansion (${\cal O}(a^2 p^2)$) are markedly reduced by HYP smearing. Compared to asqtad valence fermions, we find that taste-breaking in the pion spectrum is reduced by a factor of 2.5-3, down to a level comparable to the expected size of generic ${\cal O}(a^2)$ effects. Our results suggest that, once one reaches a lattice spacing of $a\approx 0.09$fm, taste-breaking will be small enough after HYP smearing that one can use a modified power counting in which ${\cal O}(a^2) \ll {\cal O}(p^2)$, simplify fitting to phenomenologically interesting quantities.Comment: 14 pages, 13 figures, references updated, minor change

High Tunnel Design, Site Development, and Construction

High tunnels are low technology plant growing structures that provide opportunity for season extension, severe weather protection, and modified environments to increase productivity and visual quality of harvested plant products. This publication describes high tunnel components, site selection, development, covering materials, installation, and operation. Experienced specialty plant growers can increase the quality of their products and the duration of their marketing of high- value crops through the use of high tunnels. High tunnels give growers the opportunity to plant earlier and include more sequential planting dates. This can result in early- season, high- dollar returns and the ability to offer their products for longer periods. High tunnels also provide environmental protection, which helps reduce blemishes and discoloration, improving visual appeal. For successful high tunnel crop production, decisions and actions before planting the first crop include choosing a structural design to meet specific needs, identifying the best site for locating the structure, initial soil preparation, and the method of construction

Increasing participation in the information society by people with disabilities and their families in lower-income countries using mainstream technologies

Assistive technology (AT) has been actively researched, developed and implemented throughout higher-income countries, but is relatively absent from lower-income countries. In lower-income countries, there is very little AT for reading, writing, communicating and for participation in the information society. In order for persons with disabilities in lower-income countries to participate fully in society, mainstream information and communication technologies (ICTs) such as mobile phones should be used as AT. This paper explores the potential for using mainstream ICTs as AT in lower-income countries, keeping in mind current ICT trends, characteristics of the post-PC era and ICT-based AT in higher-income countries. The paper concludes with a case study where mobile phones and SMS were used by people with disabilities and their caregivers to access information in a resourced-limited community in Bogota, Colombia. Mobile phones, a readily available mainstream ICT in this community, were a useful tool for addressing the information exclusion of people with disabilities and caregivers

Low overhead, fine-grained end-to-end monitoring of wireless networks using in-band telemetry

Wireless netWorks are becoming more complex while applications on top are becoming more demanding. To maintain network performance in terms of latency, throughput and reliability, continuous verification of the performance, possibly followed by on-the-fly network (re)configuration is needed. To achieve this, the way wireless network monitoring is being done needs to be reconsidered and should evolve towards more timely, low overhead and fine-grained monitoring. This paper shows hoiv in-band network telemetry (INT) monitoring can achieve these objectives. An INT-enabled node architecture is designed as well as novel INT options. By means of an implementation on WiFi Linux devices, the concept is validated by tracking the behavior of a real network