Long-term phosphorus effects on evolving physicochemical properties of iron and aluminum hydroxides

Iron (Fe) and aluminum (Al) hydroxides are highly reactive components in environmental processes, such as contaminant fate and transport. Phosphorus (P) sorption by these components can decrease environmental problems associated with excess accumulation of P in soils. The long-term stability of P sorbed by Fe/Al hydroxides is of major concern. Synthetic Fe and Al hydroxides coprecipitated with P (1:1 metal:P molar ratio) were incubated at 70 degrees C for 24 months to simulate natural long-term weathering processes that could influence the stability of sorbed P. Heat incubation (70 degrees C) of the untreated (no P) Al hydroxides resulted in drastic decreases (within the first month of incubation) in oxalate-Al extractability, specific surface area (SSA), and micropore volume with time. These changes were consistent with the formation of pseudoboehmite. Untreated Fe hydroxides showed no formation of crystalline components following heating (70 degrees C) for 24 months. Much smaller changes in oxalate-Al, P extractability, and SSA values were observed in the P-treated Al particles when compared with the untreated. Phosphorus treatment of both Fe and Al hydroxides stabilized the particle surfaces and prevented structural arrangements toward a long-range ordered phase. Slight reduction in SSA of the P-treated particles was related to dehydration phenomena during heating at 70 degrees C. Monitoring of physicochemical properties of the solids after heating at 70 degrees C for 2 years showed that sorbed P may be stable in the long-term. Understanding long term physicochemical properties may help engineers to optimize the Fe/Al hydroxides performance in several environmental/industrial applications.     

Nitrogen balance and delta15N: why you're not what you eat during nutritional stress

While past experiments on animals, birds, fish, and insects have shown changes in stable isotope ratios due to nutritional stress, there has been little research on this topic in humans. To address this issue, a small pilot study was conducted. Hair samples from eight pregnant women who experienced nutritional stress associated with the nausea and vomiting of morning sickness (hyperemesis gravidarum) were measured for carbon (delta13C) and nitrogen (delta15N) stable isotope ratios. The delta13C results showed no change during morning sickness or pregnancy when compared with pre-pregnancy values. In contrast, the delta15N values generally increased during periods of weight loss and/or restricted weight gain associated with morning sickness. With weight gain and recovery from nutritional stress, the hair delta15N values displayed a decreasing trend over the course of gestation towards birth. This study illustrates how delta15N values are not only affected by diet, but also by the nitrogen balance of an individual. Potential applications of this research include the development of diagnostic techniques for tracking eating disorders, disease states, and nitrogen balance in archaeological, medical, and forensic cases.     

Pyrazolo[1,5-a]pyridines as p38 kinase inhibitors

[reaction: see text] A convergent synthesis of substituted pyrazolo[1,5-a]pyridines has been achieved either via a regioselective [3 + 2] cycloaddition of N-aminopyridines with alkynes or by thermal cyclization of disubstituted azirines. Subsequent palladium-catalyzed introduction of pyridines or de novo synthesis of pyrimidines affords inhibitors of p38 kinase.     

Effect of neutrophil depletion on gelatinase expression,edema formation and hemorrhagic transformation after focal ischemic stroke

Background  

While gelatinase (MMP-2 and -9) activity is increased after focal ischemia/reperfusion injury in the brain, the relative contribution of neutrophils to the MMP activity and to the development of hemorrhagic transformation remains unknown.     

Glauberman-Watanabe corresponding -blocks of finite groups with normal defect groups are Morita equivalent

Let be a finite group and let be a solvable finite group that acts on such that the orders of and are relatively prime. Let be a -block of with normal defect group such that stabilizes and . Then there is a Morita equivalence between the block and its Watanabe correspondent block of given by a bimodule with vertex and trivial source that on the character level induces the Glauberman correspondence (and which is an isotypy by a theorem of Watanabe).

     

Observation of a resonance in Chi(1835) in J/psi --> gammapi+ pi- eta-

The decay channel J/psi --> gamma(pi)(+)pi(-)eta is analyzed using a sample of 5.8 x 10(7) J/psi events collected with the BESII detector. A resonance, the Chi(1835), is observed in the pi(+)pi(-)eta invariant-mass spectrum with a statistical significance of 7.7 sigma. A fit with a Breit-Wigner function yields a mass M = 1833.7 +/- 6.1(stat) +/- 2.7(syst) MeV/c(2), a width Tau = 67.7 +/- 20.3(stat) +/- 7.7(syst) MeV/c(2), and a product branching fraction B(J/psi --> gammaChi) . B(Chi --> pi(+)pi(-)eta) = [2.2 +/- 0.4(stat) +/- 0.4(syst)] x 10(-4). The mass and width of the Chi(1835) are not compatible with any known meson resonance. Its properties are consistent with expectations for the state that produces the strong pp mass threshold enhancement observed in the J/psi --> gammapp process at BESII.     

Generation of paired photons with controllable waveforms

We describe experiments and theory showing the generation of counterpropagating paired photons with coherence times of about 50 ns and waveforms that are controllable at a rudimentary level. Using cw lasers, electromagnetically induced transparency and cold 87Rb atoms we generate paired photons into opposing single-mode optical fibers at a rate of approximately 12 000 pairs per second.     

Near-diffraction-limited diode laser arrays by wavelength beam combining

We demonstrate 35 W output peak power with M2 approximately 1.35 in both dimensions from a 100 element, 100 microm pitch slab-coupled optical waveguide laser diode array using wavelength beam combining.     

The outer continental shelf oil and gas supply model of the energy information administration

In evaluating future United States oil and gas supplies, the Energy Information Administration (EIA) maintains separate modeling activities for the three major producing regions: the onshore lower 48 states, Alaska, and the outer continental shelf (OCS) of the lower 48 states. The choice of different modeling approaches is conditioned by the unique economic, legal, and physical environments constraining the production activities in each of these regions.This paper describes the EIA's Outer Continental Shelf Oil and Gas Supply Model (OCSM), a new model for evaluating petroleum supply from the Gulf of Mexico and the Atlantic and Pacific Oceans. OCSM is a stochastic simulation model representing the economic evaluation, exploration, and development of individual oil and gas fields. This detailed approach is supported by a unique resource base—detailed physical information on individual and as yet undiscovered structures. These data were derived from United States Geological Survey pre-lease sale tract evaluations.The model design parallels the basic activities of the offshore industry and, thus, represents the significant influence of high development costs, alternative technologies, and economies of increasing field size on OCS oil and gas supply. The effects of alternative economic scenarios, leasing rules, and development constraints on future OCS supply may be evaluated.