Kansas environmental and resource study: A Great Plains model, tasks 1-6

There are no author identified significant results in this report. Environmental and resources investigations in Kansas utilizing ERTS-1 imagery are summarized for the following areas: (1) use of feature extraction techniqued for texture context information in ERTS imagery; (2) interpretation and automatic image enhancement; (3) water use, production, and disease detection and predictions for wheat; (4) ERTS-1 agricultural statistics; (5) monitoring fresh water resources; and (6) ground pattern analysis in the Great Plains

Kansas environmental and resource study: A Great Plains model

The land use category of subimage regions over Kansas within an MSS image can be identified with an accuracy of about 70% using the textural-spectral features of the multi-images from the four MSS bands. Ground truth measurements indicate that reflectance ratios of the 545 and 655 nm wavebands provide an index of plant development and possibly physiological stress. Agricultural consultants have expressed substantial interest in work conducted on center pivot irrigation and have inquired as to how they may use ERTS-1 imagery to aid those in the irrigation field. Results of the land use mapping experiment indicate that ERTS-1 imagery has major potential in regionalization. The ways in which land is utilized within these regions may then be studied more effectively than if no adequate regionalization is available

Kansas environmental and resource study: A Great Plains model

The author has identified the following significant results. Improvement in the land use classification accuracy of ERTS-1 MSS multi-images over Kansas can be made using two distances between neighboring grey tone N-tuples instead of one distance. Much more information is contained texturally than spectrally on the Kansas image. Ground truth measurements indicate that reflectance ratios of the 545 and 655 nm wavebands provide an index of plant development and possibly physiological stress. Preliminary analysis of MSS 4 and 5 channels substantiate the ground truth interpretation. Results of the land use mapping experiment indicate that ERTS-1 imagery has major potential in regionalization. The ways in which land is utilized within these regions may then be studied more effectively than if no adequate regionalization is available. A model for estimating wheat yield per acre has been applied to acreage estimates derived from ERTS-1 imagery to project the 1973 wheat yields for a ten county area in southwest Kansas. The results are within 3% of the preharvest estimates for the same area prepared by the USDA. Visual identification of winter wheat is readily achieved by using a temporal sequence of images. Identification can be improve by stratifying the project area into subregions having more or less homogeneous agricultural practices and crop mixes

Structural characterization of nanofiber silk produced by embiopterans (webspinners)

Embiopterans produce silken galleries and sheets using exceptionally fine silk fibers in which they live and breed. In this study, we use electron microscopy (EM), Fourier-transform infrared (FT-IR) spectroscopy, wide angle X-ray diffraction (WAXD) and solid-state nuclear magnetic resonance (ssNMR) techniques to elucidate the molecular level protein structure of webspinner (embiid) silks. Silks from two species Antipaluria urichi and Aposthonia ceylonica are studied in this work. Electron microscopy images show that the fibers are about 90–100 nm in diameter, making webspinner silks among the finest of all known animal silks. Structural studies reveal that the silk protein core is dominated by β-sheet structures, and that the protein core is coated with a hydrophobic alkane-rich surface coating. FTIR spectra of native embiid silk shows characteristic alkane CH2 stretchings near 2800–2900 cm−1, which decrease approximately 50% after washing the silk with 2 : 1 CHCl3 : MeOH. Furthermore, 13C ssNMR data shows a significant CH2 resonance that is strongly affected by the presence of water, supporting the idea that the silk fibers are coated with a hydrocarbon-rich layer. Such a layer is likely used to protect the colonies from rain. FTIR data also suggests that embiid silks are dominated by β-sheet secondary structures similar to spider and silkworm silk fibers. NMR data confirms the presence of β-sheet nanostructures dominated by serine-rich repetitive regions. A deconvolution of the serine Cβ NMR resonance reveals that approximately 70% of all seryl residues exist in a β-sheet structure. This is consistent with WAXD results that suggest webspinner silks are 70% crystalline, which is the highest crystalline fraction reported for any animal silks. The work presented here provides a molecular level structural picture of silk fibers produced by webspinners

Locally Preferred Structure and Frustration in Glassforming Liquids: A Clue to Polyamorphism?

We propose that the concept of liquids characterized by a given locally preferred structure (LPS) could help in understanding the observed phenomenon of polyamorphism. ``True polyamorphism'' would involve the competition between two (or more) distinct LPS, one favored at low pressure because of its low energy and one favored at high pressure because of its small specific volume, as in tetrahedrally coordinated systems. ``Apparent polyamorphism'' could be associated with the existence of a poorly crystallized defect-ordered phase with a large unit cell and small crystallites, which may be illustrated by the metastable glacial phase of the fragile glassformer triphenylphosphite; the apparent polyamorphism might result from structural frustration, i. e., a competition between the tendency to extend the LPS and a global constraint that prevents tiling of the whole space by the LPS.Comment: 11, 6 figures, Proceedings of the Conference "Horizons in Complex Systems", Messina; in honor of the 60th birthday of H.E. Stanle

Pressure effect on the in-plane magnetic penetration depth in YBa_2Cu_4O_8

We report a study of the pressure effect (PE) on the in-plane magnetic field penetration depth lambda_{ab} in YBa_2Cu_4O_8 by means of Meissner fraction measurements. A pronounced PE on lambda_{ab}^{-2}(0) was observed with a maximum relative shift of \Delta\lambda^{-2}_{ab}/\lambda^{-2}_{ab}= 44(3)% at a pressure of 10.2 kbar. It arises from the pressure dependence of the effective in-plane charge carrier mass and pressure induced charge carrier transfer from the CuO chains to the superconducting CuO_2 planes. The present results imply that the charge carriers in YBa_2Cu_4O_8 are coupled to the lattice.Comment: 4pages 3 figure

The frustration-based approach of supercooled liquids and the glass transition: a review and critical assessment

One of the most spectacular phenomena in physics in terms of dynamical range is the glass transition and the associated slowing down of flow and relaxation with decreasing temperature. That it occurs in many different liquids seems to call for a "universal" theory. In this article, we review one such theoretical approach which is based on the concept of "frustration". Frustration in this context describes an incompatibility between extension of the locally preferred order in a liquid and tiling of the whole space. We provide a critical assessment of what has been achieved within this approach and we discuss the relation with other theories of the glass transition.Comment: 48 pages, 13 figures, submitted to J. Phys : Cond. Matte

Organic salt composition of pressure sensitive adhesives produced by spiders

Natural glues offer great potential as bio-inspired solutions to problems associated with the performance of synthetic adhesives. Spider viscous glues are elastic pressure sensitive adhesives (PSAs) that physically adhere to surfaces on contact across a range of environmental conditions. Extracting useful components from these secretions remains a challenge that can be met by the comparative analyses of functional analogues. Here we used 1H NMR spectroscopy and mass spectrometry to ascertain the organic salt compositions of the PSAs of four different species of Australian spiders belonging to two lineages that independently acquired aqueous gluey secretions: the St Andrew’s cross (Argiope keyserlingi), the redback (Latrodectus hasselti), the false widow (Steatoda grossa), and the daddy long-legs spider (Pholcus phalangiodes). The PSAs from each of these spiders contained similar organic salts, albeit in variable concentrations. The adhesives of the false widow and daddy long-legs spider had mixtures of only a few components, of which betaine predominated, while the PSAs of the other spiders predominantly contained small organic acids such as GABA/GABA-amide, isethionate, and choline salts. Our results suggest that the PSA composition of spiders is likely to be influenced more by environmental factors than evolutionary history and are guided by common principles. Our findings could be valuable for facilitating the design of more sustainable synthetic glues

Functional analysis of the sporulation-specific SPR6 gene of Saccharomyces cerevisiae

The SPR6 gene of Saccharomyces cerevisiae encodes a moderately abundant RNA that is present at high levels only during sporulation. The gene contains a long open reading frame that could encode a hydrophilic protein approximately 21 kDa in size. This protein is probably produced by the yeast, because the lacZ gene of Escherichia coli is expressed during sporulation when fused to SPR6 in the expected reading frame. SPR6 is inessential for sporulation; mutants that lack SPR6 activity sporulate normally and produce viable ascospores. Nonetheless, the SPR6 gene encodes a function that is relevant to sporulating cells; the wild-type allele can enhance sporulation in strains that are defective for several SPR functions. SPR6 is located on chromosome V, 14.4 centimorgans centromere-distal to MET6 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46973/1/294_2004_Article_BF00318210.pd