Determination of atmospheric moisture structure and infrared cooling rates from high resolution MAMS radiance data

This program has applied Multispectral Atmospheric Mapping Sensor (MAMS) high resolution data to the problem of monitoring atmospheric quantities of moisture and radiative flux at small spatial scales. MAMS, with 100-m horizontal resolution in its four infrared channels, was developed to study small scale atmospheric moisture and surface thermal variability, especially as related to the development of clouds, precipitation, and severe storms. High-resolution Interferometer Sounder (HIS) data has been used to develop a high spectral resolution retrieval algorithm for producing vertical profiles of atmospheric temperature and moisture. The results of this program are summarized and a list of publications resulting from this contract is presented. Selected publications are attached as an appendix

Oriental lily hybrids engineered to resist aphid attack

Establishing in vitro bulb scale cultures of lily cultivars followed by callusing and regeneration after gene transfer was found to be not very successful in our hands, except for ‘Snow Queen’. Identifying a more generally applicable system to generate callus with the ability to regenerate and amenable to Agrobacterium-mediated gene transfer was the goal of the research described here. Callus was induced on style and filament explants of 26 cultivars of lily. The cultivars were chosen from the hybrid groups longiflorum, asiatics and orientals of the genus Lilium but also interspecific hybrids were represented. Most cultivars were diploids but some were of triploid level and one was tetraploid. In general once callus was induced, it could relatively easily be maintained and propagated for further use. Regeneration was observed on both callus types from all cultivars tested with an efficiency ranging from 40 to 100%. Gene transfer as demonstrated by positive reporter gene uidA activity was found in all cultivars tested. Transgenic plants could be obtained in the first series of transformations and the applicability of a marker-free system was proven in lily. The protocol can now be used for the introduction of genes aiming at conferring resistance to aphids

Addressing drought conditions under current and future climates in the Jordan River region

The Standardized Precipitation–Evaporation Index (SPEI) was applied in order to address the drought conditions under current and future climates in the Jordan River region located in the southeastern Mediterranean area. In the first step, the SPEI was derived from spatially interpolated monthly precipitation and temperature data at multiple timescales: accumulated precipitation and monthly mean temperature were considered over a number of timescales – for example 1, 3, and 6 months. To investigate the performance of the drought index, correlation analyses were conducted with simulated soil moisture and the Normalized Difference Vegetation Index (NDVI) obtained from remote sensing. A comparison with the Standardized Precipitation Index (SPI), i.e., a drought index that does not incorporate temperature, was also conducted. The results show that the 6-month SPEI has the highest correlation with simulated soil moisture and best explains the interannual variation of the monthly NDVI. Hence, a timescale of 6 months is the most appropriate when addressing vegetation growth in the semi-arid region. In the second step, the 6-month SPEI was derived from three climate projections based on the Intergovernmental Panel on Climate Change emission scenario A1B. When comparing the period 2031–2060 with 1961–1990, it is shown that the percentage of time with moderate, severe and extreme drought conditions is projected to increase strongly. To address the impact of drought on the agricultural sector, the irrigation water demand during certain drought years was thereafter simulated with a hydrological model on a spatial resolution of 1 km. A large increase in the demand for irrigation water was simulated, showing that the agricultural sector is expected to become even more vulnerable to drought in the future

Homogenization of resonant chiral metamaterials

Homogenization of metamaterials is a crucial issue as it allows to describe their optical response in terms of effective wave parameters as e.g. propagation constants. In this paper we consider the possible homogenization of chiral metamaterials. We show that for meta-atoms of a certain size a critical density exists above which increasing coupling between neighboring meta-atoms prevails a reasonable homogenization. On the contrary, a dilution in excess will induce features reminiscent to photonic crystals likewise prevailing a homogenization. Based on Bloch mode dispersion we introduce an analytical criterion for performing the homogenization and a tool to predict the homogenization limit. We show that strong coupling between meta-atoms of chiral metamaterials may prevent their homogenization at all.Comment: 8 pages, 7 figure

Future of the Virginia Oyster Industry

CHESAPEAKE BAY has long been famous for its oysters. Shared by Maryland and Virginia, this natural resource contributes greatly to the economic life of about thirty Tidewater counties. Virginia oyster grounds extend approximately half way up the bay and reach far up the numerous tributaries. In addition, there are thousands of acres of oyster grounds on the Sea Side of the Eastern Shore. Despite the magnitude of the acreage adapted for growing oysters, comparatively little effort has been made to find out just how valuable the industry is to the state or to explore its possibilities for development. Federal statistics indicate that Virginia ranks as the No. 1 oyster-producing state, the yield amounting to at least 5,000,000 bushels annually. Still, it is recognized that the state\u27s oyster grounds are capable of a much higher level of production than is witnessed toda

The effect of Coulombic friction on spatial displacement statistics

The phenomenon of Coulombic friction enters the stochastic description of dry friction between two solids and the statistic characterization of vibrating granular media. Here we analyze the corresponding Fokker-Planck equation including both velocity and spatial components, exhibiting a formal connection to a quantum mechanical harmonic oscillator in the presence of a delta potential. Numerical solutions for the resulting spatial displacement statistics show a crossover from exponential to Gaussian displacement statistics. We identify a transient intermediate regime that exhibits multiscaling properties arising from the contribution of Coulombic friction. The possible role of these effects during observations in diffusion experiments is shortly discussed.Comment: 11 pages, 9 figure