"Phantom" Inflation in Warped Compactification

In this paper, in a class of warped compactifications with the brane/flux annihilation, we find that the inflation may be driven by a flat direction identified as that along the number p of anti D3-branes located at the tip of the Klebanov-Strassler throat. The spectrum of adiabatic perturbation generated during inflation is nearly scale invariant, which may be obtained by using the results shown in the phantom inflation, since in a four-dimension effective description the evolution of energy density along the $p$ direction is slowly increasing.Comment: 5 pages, 2 figures, some arguments on the reliability of our resulits added, ref. added, to publish in PRD, matched to published versio

Controls on winter ecosystem respiration in temperate and boreal ecosystems

Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (Reco) of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter Reco rates (0.90 ± 0.39 g C m-2 d-1), when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter Reco rates (0.02 ± 0.02 g C m-2 d-1). Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter Reco rates (g C m-2 d-1) of 0.70(±0.33), 0.60(±0.38), 0.62(±0.43), 0.49(±0.22) and 0.27(±0.08), respectively. Our cross site analysis showed that winter air (Tair) and soil (Tsoil) temperature played a dominating role in determining the spatial patterns of winter Reco in both forest and managed ecosystems (grasslands and croplands). Besides temperature, the seasonal amplitude of the leaf area index (LAI), inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for Reco in the subsequent winter, played a marginal role in winter CO2 emissions from forest ecosystems. We found that winter Reco sensitivity to temperature variation across space (QS) was higher than the one over time (interannual, QT). This can be expected because QS not only accounts for climate gradients across sites but also for (positively correlated) the spatial variability of substrate quantity. Thus, if the models estimate future warming impacts on Reco based on QS rather than QT, this could overestimate the impact of temperature change

Improved Draft Genome Sequence of Microbacterium sp. Strain LKL04, a Bacterial Endophyte Associated with Switchgrass Plants.

We report here the genome assembly and analysis of Microbacterium strain sp. LKL04, a Gram-positive bacterial endophyte isolated from switchgrass plants (Panicum virgatum) grown on a reclaimed coal-mining site. The 2.9-Mbp genome of this bacterium was assembled into a single contig encoding 2,806 protein coding genes

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.This paper covers considerations in VFD applications, plus details a study performed by the Irrigation Training and Research Center (ITRC) to determine motor performances under varying speeds (controlled by a VFD) and loads

Brane Inflation from Rotation of D4 Brane

In this paper, a inflationary model from the rotation of D4-brane is constructed. We show that for a very wide rage of parameter, this model satisfies the observation and find that regarded as inflaton, the rotation of branes may be more nature than the distance between branes. Our model offers a new avenue for brane inflation.Comment: 6 pages, no figure

Finite Element Modeling of Small-Scale Tapered Wood-Laminated Composite Poles with Biomimicry Features1

Tapered composite poles with biomimicry features as in bamboo are a new generation of wood laminated composite poles that may some day be considered as an alternative to solid wood poles that are widely used in the transmission and telecommunication fields. Five finite element models were developed with ANSYS to predict and assess the performance of five types of composites members: a tapered hollow pole with webs (Pole-A), a tapered hollow pole without webs (Pole-B), a tapered solid composite pole (Pole-C), a uniform-diameter hollow pole with webs (Pole-D), and a uniform-diameter hollow pole without webs (Pole-E). The predicted deflection by these models agreed well with those of the experiment, and the predicted normal stress agreed with those calculated. The normal and shear stress distributions inside the members were investigated, and stress distributions in the XY and YZ planes are exhibited. As expected, the webs reduced the local shear stress and improved shear capacity, especially in the top and groundline regions where shear levels were the highest. The webs had little effect on the normal stress. Shear stress increased from the bottom to the top for the members with taper. Large shear stress concentration was predicted in a small region close to the groundlines. The models also predicted that the shear stress of the tapered hollow poles would decrease from the inside to the outside surfaces in XY plane