Ratios Similar (ratio + similar)

Distribution by Scientific Domains


Selected Abstracts


Reverse modelling for seismic event characterization

GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2005
Dirk Gajewski
SUMMARY The localization of seismic events is of utmost importance in seismology and exploration. Current techniques rely on the fact that the recorded event is detectable at most of the stations of a seismic network. Weak events, not visible in the individual seismogram of the network, are missed out. We present an approach, where no picking of events in the seismograms of the recording network is required. The observed wavefield of the network is reversed in time and then considered as the boundary value for the reverse modelling. Assuming the correct velocity model, the reversely modelled wavefield focuses on the hypocentre of the seismic event. The origin time of the event is given by the time where maximum focussing is observed. The spatial extent of the focus resembles the resolution power of the recorded wavefield and the acquisition. This automatically provides the uncertainty in the localization with respect to the bandwidth of the recorded data. The method is particularly useful for the upcoming large passive networks since no picking is required. It has great potential for localizing very weak events, not detectable in the individual seismogram, since the reverse modelling sums the energy of all recorded traces and, therefore, enhances the signal-to-noise ratio similar to stacking in seismic exploration. The method is demonstrated by 2-D and 3-D numerical case studies, which show the potential of the technique. Events with a S/N ratio smaller than 1 where the events cannot be identified in the individual seismogram of the network are localized very well by the method. [source]


Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score of three Mediterranean cephalopods

MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 10 2006
Spiros Zlatanos
Abstract Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score (PDCAAS) in three commercially important cephalopods of the Mediterranean sea (cuttlefish, octopus and squid) were determined. The results of the proximate analysis showed that these species had very high protein:fat ratios similar to lean beef. Docosahexaenoic, palmitic and eicosipentaenoic acid were the most abundant fatty acids among analyzed species. The amount of n- 3 fatty acids was higher than that of saturated, monounsaturated and n- 6 fatty acids. Despite the fact that cephalopods contain small amounts of fat they were found quite rich in n- 3 fatty acids. Finally, PDCAAS indicated that these organisms had a very good protein quality. [source]


Eating between the Lines: Mississippian Migration and Stable Carbon Isotope Variation in Fort Ancient Populations

AMERICAN ANTHROPOLOGIST, Issue 3 2009
Robert A. Cook
ABSTRACT Appreciating variation along the edges of traditional archaeological Culture Historical boundaries requires close consideration of social contexts associated with culture contact. We focus on dietary variation as a function of these concerns through a case study of Fort Ancient populations who, on average, consumed lower quantities of maize than their Mississippian neighbors as determined by stable carbon isotope ratios of bone collagen. However, this dichotomy is not as rigid as initially thought, with some Fort Ancient burials producing stable carbon isotope ratios similar to Mississippian cases. Detailed investigation of internal variation of carbon isotopes for human burials at the SunWatch site provides evidence that contact included small-scale Mississippian migrations to Fort Ancient sites. The main conclusion is that variation in diet and archaeological context can be a useful approach for examining prehistoric migration. [source]


Human 18 kDa phosphotyrosine protein phosphatase (ACP1) polymorphism: studies of rare variants provide evidence that substitutions within or near alternatively spliced exons affect splicing result

ANNALS OF HUMAN GENETICS, Issue 2 2000
L. RUDBECK
The mammalian low molecular weight phosphotyrosine protein phosphatase is expressed as two distinct isoforms. The human ,fast' and ,slow' isoforms differ only in the sequence of an internal segment of 34 residues, and the ACP1 gene contains two adjacent exons (E3F and E3S) which encode these segments. We have previously suggested that the fast and slow isoforms are generated by mutually exclusive pre-mRNA splicing of E3F and E3S. The common alleles ACP1*A, *B and *C express the fast and slow isoforms in different ratios. The *A and *C alleles differ from *B by C , T transitions in E3S and E3F respectively. To test the idea that the fast:slow ratio is determined by nucleotide substitutions in the E3F-I3F-E3S region, four groups of rare ACP1 variants with unusual fast : slow ratios and the rare *E and *R alleles, expressing fast : slow ratios similar to *C and *B, respectively, were analysed. Gene segments of the I2-I3S region were amplified by PCR and analysed by SSCP and variant bands were excised and sequenced. For each of the rare isozymic variants one of six different nucleotide substitutions in E3F (nts+42, +85, +109, +110), I3F (nt+1) and I3S (nt+8) was observed. The *E and *R alleles showed C and B sequence, respectively, in accordance with the fast : slow ratio. The results support the hypothesis that the fast : slow ratio is constitutive. [source]