Energetic charged particles in the uranian magnetosphere

During the encounter with Uranus, the cosmic ray system on Voyager 2 measured significant fluxes of energetic electrons and protons in the regions of the planets magnetosphere where these particles could be stably trapped. The radial distribution of electrons with energies of megaelectron volts is strongly modulated by the sweeping effects ofthe three major inner satellites Miranda, Ariel, and Umbriel. The phase space density gradient of these electrons indicates that they are diffusing radially inward from a source in the outer magnetosphere or magnetotail. Differences in the energy spectra of protons having energies of approximately 1 to 8 megaelectron volts from two different directions indicate a strong dependence on pitch angle. From the locations of the absorption signatures observed in the electron flux, a centered dipole model for the magnetic field of Uranus with a tilt of 60.1 degrees has been derived, and a rotation period of the planet of 17.4 hours has also been calculated. This model provides independent confirmaton of more precise determinations made by other Voyager experiments.     

Evaluation of bacterial strains isolated from oil-contaminated soil for production of polyhydroxyalkanoic acids (PHA)

Samples of eight geographically distinct soils contaminated with crude oil were screened for polyhydroxyalkanoic acid (PHA) producing bacterial strains. Twenty three bacterial strains were able to accumulate PHA when sodium gluconate or sodium octanoate was used as the sole carbon source. Biochemical tests and 16S rRNA sequencing identified bacteria of the genera Pseudomonas, Acinetobacter, Sphingobacterium, Brochothrix, Caulobacter, Ralstonia, Burkholderia and Yokenella. Three of the bacterial strains have never been reported to produce PHA. The phylogenetic analysis of the PHA synthase (phaC) gene of these bacteria showed a close homology with the phaC gene of different Pseudomonas species.This study indicates that stressed environments like oil-contaminated sites can be potential sources of medium-chain-length PHA producers.     

Pattern of bombardment-produced radionuclides in rock 10017 and in lunar soil

A large number of radionuclides have been measured as a function of depth in lunar rock 10017 and in bulk fines. Data are reported on (10)Be, (22)Na, (26)Al, (36)Cl, (49)V, (53)mn, (54)Mn (55)Fe, (56)Co, (57)Co, and (59)Ni and on upper limits for (46)Sc, (48)V, (51)Cr, and (60)Co. The results for several nuclides show striking evidence of excess surface production attributable to solar flare particles. Data for short-lived species, (56)Co, (57)CO, (54)Mn, (55)Fe, and (22)Na, appear consistent with fluxes from known recent events. Long-lived species demonstrate the existence of solar flare protons and alphas at least for the last 10(5) to 10(6) years, at fluxes comparable to those now observerved.     

Atomic force microscopy and dissection of gap junctions

An atomic force microscope (AFM) was used to study the structure of isolated hepatic gap junctions in phosphate-buffered saline (PBS). The thickness of these gap junctions appears to be 14.4 nanometers, close to the dimensions reported by electron microscopy (EM). When an increasing force is applied to the microscope tip, the top membrane of the gap junction can be "dissected" away, leaving the extracellular domains of the bottom membrane exposed. When such "force dissection" is performed on samples both trypsinized and fixed with glutaraldehyde, the hexagonal array of gap junction hemichannels is revealed, with a center-to-center spacing of 9.1 nanometers.     

Remote Sensing of Soil and Water Quality in Agroecosystems

Mismanagement of soil and water resources may not only contribute to an escalation of global poverty but also jeopardize ecosystem services, with significant costs to the environment. Although not concentrated within one geographic location (3,500 million hectares), an equivalent of approximately 24 % of the earth’s land surface is degraded land, and about 2 billion people (one third of the global population) lack access to safe and affordable water for domestic purposes. It is therefore critical to develop strategies targeted at the root causes of these problems. However, to do so would require a rapid and reliable information system that has been elusive because of the complexity of the environment and the limitations of the existing tools. The increased availability and development of remote sensing and geographic data analysis tools have opened up new possibilities for exploring and monitoring environmental variables influencing key land use and soil management options. Here, we explore the major concepts, describe the constraints, and the future potential of remote sensing for mapping and providing near real-time information on soil and water quality in the context of major land use practices employed at the global scale.     

Soil fertility in flooded and non-flooded irrigated rice systems

The lowland rice system in Asia makes a major contribution to the global rice supply and is often cited as an example of a sustainable system in which two or three crops of rice are grown in sequence under submerged conditions. However, water shortages are becoming critical in some regions for lowland rice cultivation; and there is high potential in exploring rice cultivation under moisture regimes that save water and also increase productivity. The objective of this article therefore is to analyze the consequences of switching growing of rice from flooded to aerobic conditions on soil fertility and its management. Fertility advantages of submerged rice include amelioration of chemical fertility, preferential accumulation of organic matter and improved availability of major, secondary and selected micronutrients, which contribute to the long-term maintenance of soil fertility and sustainability of the lowland rice system. However, the fertility problems under aerobic rice are better addressed with the crop as a component of a cropping system because continuous growing of aerobic rice in sequence does not seem sustainable due to complex, site-specific chemical and biological constraints.     

Assessing soil spatial variability and delineating site-specific management zones for a coastal saline land in eastern India

ABSTRACT

The present study was to delineate management zones (MZs) in salt affected Mahakalpada block in eastern India by capturing both spatial variability of soil parameters along with satellite derived Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). Grid wise 237 soil samples collected from the study area were analyzed and spatial maps were generated for physicochemical properties, DTPA extractable micronutrients, i.e. iron, zinc, copper, and manganese and major nutrients, i.e. available nitrogen (AN), phosphorous (AP), and potassium (AK). Soil electrical conductivity and AK showed a high CV of 100% and 56.7%, respectively. Principal component analysis was performed using the soil spatial maps, NDVI and EVI maps and only four principal components which produced eigenvalues > 1 and accounting for 75.4% of the total variability were retained for further analysis. Further, fuzzy c-mean clustering was used to delineate the MZs based on fuzzy performance index (FPI) and normalized classification entropy (NCE) was used for identifying the three MZs. There was a significant difference between MZ1 and MZ2 for all the variables except AN and EVI whereas all the variables were significantly different between MZ1 and MZ3 highlighting the usefulness of MZs delineation technique for site-specific nutrient management.