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131.
132.
Nidhi Nagabhatla R. Wickramasuriya S. N. Prasad 《Journal of the Indian Society of Remote Sensing》2009,37(3):443-455
The present study investigates the potential of readily available and easily accessible global data sets to understand regional/local
level interactions in wetland systems. The biogeographical zones of India were used a base-frame to select three sites. The
study well fits the interests of National Wetland Committee of India to investigate and document fundamental information on
wetland extent/distribution. The national partnership with SACON represents this interest. SACON commenced the inland wetland
inventory module at national scale using geospatial data, although the provincial scale analysis is underway. In addition,
the global irrigated area mapping (GIAM-IWMI) project generated multi-scalar spatial outputs for irrigated/rain-fed areas.
With the existing information base, a multi-level geospatial analysis using Arc GIS algorithmic modelling was used to derive
comprehensive appraisal of wetland systems complementing the data from GIAM and SACON. It was observed that the overlap between
the two layers was 58 percent for Gujarat and 10 percent in Tamil Nadu. In Krishna basin the wetland’s cover 1.04 million
hectare excluding the rice agro-ecosystem. The difference in the biogeography of the case sites governs the gradient of information
derived from both data layers. Additionally, the global lakes and wetlands database (GLWD) database added thematic information
on coastal wetlands. In summary we describe the cross-scaling the global data layers to compliment the regional/national level
monitoring assignments. 相似文献
133.
Elvis A. Shukla Jagdish Prasad M. S. S. Nagaraju Rajeev Srivastava D. L. Kauraw 《Journal of the Indian Society of Remote Sensing》2009,37(1):129-137
Soil resource characterization of Dhamni micro-watershed in Chandrapur district of Maharashtra was carried out using IRS-1D
LISS-III data in conjunction with field survey and ancillary data. The study indicates that nearly 84.2 per cent of the total
geographical area of the watershed is under cultivation. Forest (mainly degraded) occupy only 4.5 per cent area Whereas wasteland
with scrub cover 9.4 per cent area of the watershed. Nine soil series were tentatively identified and mapped as soil series
association in to five mapping units. These soils belong to order Inceptisol, Vertisol and Mollisol. Except the soils of wasteland
with scrub, other soils are moderately suitable for pigeonpea and soybean and have average to good productivity. 相似文献
134.
Conventions on thermal expansion modelling of radio telescopes for geodetic and astrometric VLBI 总被引:7,自引:6,他引:1
Axel Nothnagel 《Journal of Geodesy》2009,83(8):787-792
Thermal expansion of radio telescopes has long been recognized as an effect which cannot be neglected in geodetic and astrometric
VLBI data analysis if millimeter accuracy is desired. In this article, the author documents the conventions which are being
set by the International VLBI Service for Geodesy and Astrometry (IVS) for a consistent modelling of this effect in its routine
product generation. For the largest telescopes, the annual cycle of thermal expansion may change the height of the VLBI reference
point by as much as 20 mm. However, for telescopes which are used in present-day IVS operations, the variations rather range
from 4 to 6 mm. 相似文献
135.
Michiel A. F. Knaapen 《Geo-Marine Letters》2009,29(1):17-24
Sandbanks, the largest of bed patterns in shallow sandy seas, pose a potential risk to shipping. They are also valuable elements
of natural coastal protection, dissipating the energy of waves. In the Southern Bight of the North Sea, several sandbank areas
have been reported in the literature. However, based on an objective crest–trough analysis of the bathymetry of the Dutch
continental shelf, the present study shows that sandbanks are more widespread than commonly considered. These banks are relatively
low, presumably explaining why they have not been documented before. This widespread occurrence of sandbanks in the North
Sea is in agreement with theoretical predictions based on stability analysis techniques. The possible interference between
large-scale human activity and low-amplitude open-shelf ridges implies that one should be careful not to overlook these patterns
if none should appear in a preliminary (visual) assessment. The only part of the Southern Bight in which no ridges can be
seen is a circular area with a diameter of about 50 km near the mouth of the river Rhine. Here, freshwater outflow affects
the direction of tidal ellipses and residual flow, and suppresses the formation of open ridges. 相似文献
136.
Pockmarks in the inner Oslofjord,Norway 总被引:5,自引:3,他引:2
Multibeam bathymetric surveys of the Inner Oslofjord, Norway have revealed a high density of pockmarks in the 179-km2 inner fjord area, which contains over 500 pockmarks of varying size, typically 20–50 m in diameter and 2–10 m deep. These
pockmarks have been investigated with a variety of techniques, including acoustic subbottom profiling, sedimentological and
geochemical analyses of cores, remotely operated vehicle observation, and morphometry. Both the distribution and shapes of
the pockmarks suggest that they are related to structures in the bedrock underlying relatively thin (<50 m) unconsolidated
glacial and postglacial sediments. The data provide no direct indication of a particular mode of pockmark formation, but release
of large amounts of biogenic, shallow methane seems unlikely. Several lines of evidence point to a continuous process of pockmark
formation followed by inactivity, with some pockmarks recently active whereas others have been inactive for a considerable
time. Some pockmarks are characterised by coarse sediment in their centres. The density, variety and easy access make this
pockmark field an ideal model area for pockmark research.
John S. Gray is deceased. 相似文献
137.
Jeff A. Polton 《Journal of Oceanography》2009,65(5):665-668
In a recent paper, Liu et al. (2007) formulate an expression for how surface gravity waves modify the Ekman layer energy budget. They then diagnose the
effect in the world oceans using available data. This comment addresses the formulation of the energy equation that is fundamental
to their study. 相似文献
138.
Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 (PP1) is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase l(PPlcb), was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPPlcb, by the rapid amplification of cDNA ends (RACE) technique. The cDNA sequence of SmPPlcb we obtained contains a 984 bp open reading frame (ORF), flanked by a complete 39 bp 5' untranslated region and 462 bp 3' untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B (PP2B). And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPPlcb is extremely conserved in both amino acid and nucleotide acid levels compared with the PPlcb of other vertebrates and invertebrates, and its Kozak motif contained in the 5'UTR around ATG start codon is GXXAXXGXXATGG, which is different from mammalian in two positions A6 and G3, indicating the possibility of different initiation of translation in turbot, and also the 3'UTR of SmPPlcb is highly diverse in the sequence similarity and length compared with other animals, especially zebraf'lsh. The cloning and sequencing of SmPPlcb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot. 相似文献
139.
We isolated 4 Norwalk-like viruses (NLVs) contaminated oysters from 33 Chinese oysters collected from local commer-cial sources of Shandong Province. After amplification of the RNA-dependent RNA polymerase (RdRp) region of NLVs genomes with RT-PCR, the open reading frame 1 (ORF1) of the RdRp was sequenced and subjected to multiple-sequence alignment. The re-suits showed that NLVs in the four isolates belong to genogroup Ⅱ. The sequence comparison showed that the similarity between four Chinese oyster isolates were higher than 99.0%, which indicated that NLVs prevalent in close areas have high homogeneity in genome sequences. In addition, the most conserved sequences between diverse NLVs were used to design primers and TaqMan probes, then the real-time quantitative PCR assay was performed. According to the standard curve of GII NLVs, the original amounts (copies) of NLVs in positive patient's fecal isolate, positive Japanese oyster isolate, and the Chinese oyster isolate were 8.9×108, 1.25×108 and 4.7×101 respectively. The detecting limit of NLVs was 1×101 copies. This study will be helpful for routine diagnosis of NLVs pathogens in foods and thus for avoiding food poisoning in the future. 相似文献
140.
Luca Cavallaro Antonino Viviano Giovanni Paratore Enrico Foti 《Ocean Science Journal》2018,53(3):461-474
Surface wave interaction with aquatic vegetation appears to play a key role in coastal hydro-morpho-dynamics. As an example, the presence of a dense meadow at intermediate water depth is usually associated with a stable and resilient shore. Wave-meadow interactions are investigated here by means of physical modelling, with a focus on wave height distribution and hydrodynamics. The central part of a wave flume is covered by flexible artificial seagrass, composed of polyethylene leaves. This vegetation is tested in both near emergent and submerged conditions. The wave height reduction is evaluated by means of a drag coefficient defined from linear wave theory, which contains all the unknowns of the adopted methodology. The behaviour of such a coefficient is investigated as a function of a wave related Reynolds number. The influence of the flexibility of the leaves is also considered, together with a wave frequency parameter. The results show a complex behaviour with three different trends for near rigid, intermediate or highly flexible leaves. Amplitudes of the orbital velocities are investigated and show a fairly good match with the linear wave theory. On the contrary, the mean velocity along the water column appears to be modified by the seagrass for submerged leaves. 相似文献