Feasibility of Estimating Relative Nutrient Contributions of Agriculture using MODIS Time Series

Around the Gulf of Mexico, high-input crops in several regions make a significant contribution to nutrient loading of small to medium estuaries and to the near-shore Gulf. Some crops cultivated near the coast include sorghum in Texas, rice in Texas and Louisiana, sugarcane in Florida and Louisiana, citrus orchards in Florida, pecan orchards in Mississippi and Alabama, and heavy sod and ornamental production around Mobile and Tampa Bay. In addition to crops, management of timberlands in proximity to the coasts also plays a role in nutrient loading. In the summer of 2008, a feasibility project is planned to explore the use of NASA data to enhance the spatial and temporal resolution of near-coast nutrient source information available to the coastal community. The purpose of this project is to demonstrate the viability of nutrient source information products applicable to small to medium watersheds surrounding the Gulf of Mexico. Conceptually, these products are intended to complement estuarine nutrient monitoring

Feasibility of Estimating Relative Nutrient Contributions of Agriculture and Forests Using MODIS Time Series

Around the Gulf of Mexico, high-input crops in several regions make a significant contribution to nutrient loading of small to medium estuaries and to the near-shore Gulf. Some crops cultivated near the coast include sorghum in Texas, rice in Texas and Louisiana, sugarcane in Florida and Louisiana, citrus orchards in Florida, pecan orchards in Mississippi and Alabama, and heavy sod and ornamental production around Mobile and Tampa Bay. In addition to crops, management of timberlands in proximity to the coasts also plays a role in nutrient loading. In the summer of 2008, a feasibility project is planned to explore the use of NASA data to enhance the spatial and temporal resolution of near-coast nutrient source information available to the coastal community. The purpose of this project is to demonstrate the viability of nutrient source information products applicable to small to medium watersheds surrounding the Gulf of Mexico. Conceptually, these products are intended to complement estuarine nutrient monitoring

Intermixing at the InxSy/Cu2ZnSn(S,Se)4 Heterojunction and Its Impact on the Chemical and Electronic Interface Structure

We report on the chemical and electronic structure of the interface between a thermally co-evaporated InxSy buffer and a Cu2ZnSn(S,Se)4 (CZTSSe) absorber for thin-film solar cells. To date, such cells have achieved energy conversion efficiencies up to 8.6%. Using surface-sensitive X-ray and UV photoelectron spectroscopy, combined with inverse photoemission and bulk-sensitive soft X-ray emission spectroscopy, we find a complex character of the buffer layer. It includes oxygen, as well as selenium and copper that diffused from the absorber into the InxSy buffer, exhibits an electronic band gap of 2.50 ± 0.18 eV at the surface, and leads to a small cliff in the conduction band alignment at the InxSy/CZTSSe interface. After an efficiency-increasing annealing step at 180 °C in nitrogen atmosphere, additional selenium diffusion leads to a reduced band gap at the buffer layer surface (2.28 ± 0.18 eV)

Monitoring Phenology as Indicator for Timing of Nutrient Inputs in Northern Gulf Watersheds

Nutrient over-enrichment defined by the U.S. Environmental Protection Agency as the anthropogenic addition of nutrients, in addition to any natural processes, causing adverse effects or impairments to the beneficial uses of a water body has been identified as one of the most significant environmental problems facing sensitive estuaries and coastal waters. Understanding the timing of nutrient inputs into those waters through remote sensing observables helps define monitoring and mitigation strategies. Remotely sensed data products can trace both forcings and effects of the nutrient system from landscape to estuary. This project is focused on extracting nutrient information from the landscape. The timing of nutrients entering coastal waters from the land boundary is greatly influenced by hydrologic processes, but can also be affected by the timing of nutrient additions across the landscape through natural or anthropogenic means. Non-point source nutrient additions to watersheds are often associated with specific seasonal cycles, such as decomposition of organic materials in fall and winter or addition of fertilizers to crop lands in the spring. These seasonal cycles or phenology may in turn be observed through the use of satellite sensors. Characterization of the phenology of various land cover types may be of particular interest in Gulf of Mexico estuarine systems with relatively short pathways between intensively managed systems and the land/estuarine boundary. The objective of this study is to demonstrate the capability of monitoring phenology of specific classes of land, such as agriculture and managed timberlands, at a refined watershed level. The extraction of phenological information from the Moderate Resolution Imaging Spectroradiometer (MODIS) data record is accomplished using analytical tools developed for NASA at Stennis Space Center: the Time Series Product Tool and the Phenological Parameters Estimation Tool. MODIS reflectance data (product MOD09) were used to compute the Normalized Difference Vegetation Index, which is sensitive to changes in vegetation canopies. The project team is working directly with the Mississippi Department of Environmental Quality to understand end-user requirements for this type of information product. Initial focus areas are identification of time frames for pre-plant fertilizer applications (prior to start of season), side-dress fertilizer applications (during rapid green-up), and periods of plant decomposition (during and after senescence). Prototypical maps of phenological stages related to these time frames have been generated for watersheds in the northern Gulf of Mexico. Where feasible, these maps have been compared to existing in situ nutrient monitoring data, but the in situ data is temporally sparse (monthly frequency or less), which makes interpretation challenging. Future work will include integrating effects of rainfall and seeking couplings with estuarine remote sensing

Flux of Primordial Monopoles

We discuss how in supersymmetric models with D and F-flat directions, a primordial monopole flux of order 10^{-16} - 10^{-18} cm^{-2} sec^{-1} sr^{-1} can coexist with the observed baryon asymmetry. A modified Affleck-Dine scenario yields the desired asymmetry if the monopoles are superheavy (~ 10^{13}-10^{18} GeV). For lighter monopoles with masses ~ 10^{9}-10^{12} GeV, the baryon asymmetry can arise via TeV scale leptogenesis.Comment: 17 pages, 4 figures, revtex

Neutrino Astrophysics in the cold: Amanda, Baikal and IceCube

This talk review status and results from the two presently operating underwater/ice neutrino telescopes, NT-200 in Lake Baikal and Amanda-II at the South Pole. It also gives a description of the design and the expected performance of Icecube, the next-generation neutrino telescope at South Pole.Comment: Talk given at the Nobel Symposium on Neutrino Physics, Haga Slott, Sweden, 2004, 14 pages, 10 figure

Drug mechanisms to help in managing resistant hypertension in obesity

Obesity is a major risk factor for the development of hypertension. Because the prevalence of obesity is increasing worldwide, the prevalence of obesity hypertension is also increasing. Importantly, hypertension in obesity is commonly complicated by dyslipidemia and type 2 diabetes mellitus and hence imposes a high cardiovascular disease risk. Furthermore, obesity is strongly associated with resistant hypertension. Activation of the sympathetic nervous system and the renin-angiotensin system, leading to renal sodium and water retention, links obesity with hypertension. There is also evidence for the release of factors by visceral adipose tissue promoting excessive aldosterone production, and a more central role of aldosterone in obesity hypertension is emerging. Randomized studies evaluating the effect of different classes of antihypertensive agents in obesity hypertension are scarce, short-lasting, and small. Considering the emerging role of aldosterone in the pathogenesis of obesity hypertension, mineralocorticoid receptor antagonism may play a more central role in the pharmacologic treatment of obesity hypertension in the near future

Charges on Strange Quark Nuggets in Space

Since Witten's seminal 1984 paper on the subject, searches for evidence of strange quark nuggets (SQNs) have proven unsuccessful. In the absence of experimental evidence ruling out SQNs, the validity of theories introducing mechanisms that increase their stability should continue to be tested. To stimulate electromagnetic SQN searches, particularly space searches, we estimate the net charge that would develop on an SQN in space exposed to various radiation baths (and showers) capable of liberating their less strongly bound electrons, taking into account recombination with ambient electrons. We consider, in particular, the cosmic background radiation, radiation from the sun, and diffuse galactic and extragalactic $\gamma$-ray backgrounds. A possible dramatic signal of SQNs in explosive astrophysical events is noted.Comment: CitationS added, new subsection added, more discussion, same numerical result