Q-mode Factor Analysis Research Articles

A Clustering Method for Discovering Patterns Using Gene Regulatory Processes

Clustering is a descriptive task that seeks to identify homogeneous groups of objects based on the values of their attributes (dimensions). The k-means and hierarchical as well as self-organizing maps have all been used for clustering expression profiles and a number of algorithms have been developed for expression data and applied to analyze it. These Clustering methods usually use metric distance for similarity measure. Correlation coefficient is also used but has a problem that it removes difference attributable to both the mean and the dispersion of the observations. Moreover, it may be unreasonable that every observation is assigned to one of clusters when the purpose is to find groups with similar pattern. Alter et al. [1] show that several significant eigengenes and the corresponding eigenarrays capture most of the expression information in field of genetics and some of the eigengenes represent independent regulatory programs or processes from its expression pattern across all arrays. Normalizing the data by filtering out the eigengenes (and the corresponding eigenarrays) that are inferred to represent noise or experimental artifacts enables meaningful comparison of the expression of different genes across different arrays in different expression. Such normalization may improve any further analysis of the expression data. Q-mode factor analysis has been used to find groups like clustering analysis and could be a good method to find patterns. However, this approach to clustering is plagued with a number of problems [3]. Genes with similar expression profiles may have something in common in their regulatory mechanisms. In this study, Q-mode factor analysis is used to model the gene regulatory processes which control genes and gene products and we modify the Q-mode factor analysis for discovering useful patterns in gene expression data. As a result of the factor modeling of gene expression data, our method can improve the result of clustering by removing noises and produce characteristic values of expression data.

Imbrie’s Q-Mode Factor Analysis Applied to Simultaneous Determination of Individual Amino Acid in Binary and Ternary Mixtures

Imbrie’s Q-Mode Factor Analysis Applied to Simultaneous Determination of Individual Amino Acid in Binary and Ternary Mixtures

Speciation of aqueous chromium(VI) solutions with the aid of Q-mode factor analysis followed by oblique projection

The identities of the species of chromium(VI) that are present in aqueous solution, their spectra and their equilibria, continue to be a subject of discussion in the literature. In this paper, the composition of the Cr(VI) equilibria was estimated from the UV–vis spectra of dilute potassium dichromate solutions, without any prior knowledge of the quantities of pure components, with the aid of Imbrie Q-mode factor analysis (Q-mode FA) followed by Varimax rotation and Imbrie oblique projection. Combining these results with the k-matrix method, it was possible to obtain the spectra of the individual Cr(VI) species. Sets of 3.3×10 −4 and 3.3×10 −5 mol l −1 Cr(VI) solutions were studied. In the pH range from 1 to 12, two factors were identified, which were related to the two species, chromate ion (CrO 4 2−) and bichromate ion (HCrO 4 −). When the analysis was extended to concentrated acid media, another factor appeared, which was related to chromic acid (H 2CrO 4). No evidence for the dichromate ion (Cr 2O 7 2−) was seen at the Cr(VI) concentrations used. The spectra of the pure components were obtained and p K values for the first and second chromic acid dissociations were estimated as −0.54 and 5.8, respectively.

DISTRIBUTION AND OCEANOGRAPHIC RELATIONSHIPS OF MODERN PLANKTONIC FORAMINIFERA IN THE RYUKYU ARC REGION, NORTHWEST PACIFIC OCEAN

Research Article| October 01, 2000 DISTRIBUTION AND OCEANOGRAPHIC RELATIONSHIPS OF MODERN PLANKTONIC FORAMINIFERA IN THE RYUKYU ARC REGION, NORTHWEST PACIFIC OCEAN Yurika Ujiie; Yurika Ujiie 1Ocean Research Institute, University of Tokyo, Minami-dai 1-15-1, Nakano-ku, Tokyo 164-8639, Japan. E-mail: yurika@ori.u-tokyo.ac.jp Search for other works by this author on: GSW Google Scholar Hiroshi Ujiie Hiroshi Ujiie 2Professor Emeritus, University of the Ryukyus; Izumi-cho 1156-4-338, Tachikawa City, Tokyo 190-0015, Japan. E-mail: ujiie@green.ocn.ne.jp Search for other works by this author on: GSW Google Scholar Author and Article Information Yurika Ujiie 1Ocean Research Institute, University of Tokyo, Minami-dai 1-15-1, Nakano-ku, Tokyo 164-8639, Japan. E-mail: yurika@ori.u-tokyo.ac.jp Hiroshi Ujiie 2Professor Emeritus, University of the Ryukyus; Izumi-cho 1156-4-338, Tachikawa City, Tokyo 190-0015, Japan. E-mail: ujiie@green.ocn.ne.jp Publisher: Cushman Foundation for Foraminiferal Research Received: 26 Jul 1999 Accepted: 19 May 2000 First Online: 03 Mar 2017 Online ISSN: 1943-264X Print ISSN: 0096-1191 © 2000 Journal of Foraminiferal Research Journal of Foraminiferal Research (2000) 30 (4): 336–360. https://doi.org/10.2113/0300336 Article history Received: 26 Jul 1999 Accepted: 19 May 2000 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Yurika Ujiie, Hiroshi Ujiie; DISTRIBUTION AND OCEANOGRAPHIC RELATIONSHIPS OF MODERN PLANKTONIC FORAMINIFERA IN THE RYUKYU ARC REGION, NORTHWEST PACIFIC OCEAN. Journal of Foraminiferal Research 2000;; 30 (4): 336–360. doi: https://doi.org/10.2113/0300336 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyJournal of Foraminiferal Research Search Advanced Search Abstract Recent planktonic foraminifera were analyzed in 52 surface sediment samples collected from the Ryukyu Arc region in the northwestern Pacific Ocean and adjacent East China Sea with the goals of establishing relationships between species distributions and oceanographic features with emphasis on the Kuroshio Current. Thirty-nine species of planktonic foraminifera were identified and grouped into 27 species and species groups based upon taxonomic and ecologic criteria. Calculation of a correlation matrix in the form of a similarity index allowed for a comparison of the relative abundances of the 27 species and species groups within and among all sample sites. Q-mode cluster analysis was subsequently applied using the UPGMA method, and five major site clusters A to E were distinguished. The geographic distribution of samples in site cluster A coincides well with the distribution of higher loading values of factor 2, identified by Q-mode factor analysis carried out using the same coefficient matrix. Similar associations were established for site cluster C-1 with those of factor 1, and site clusters C-2, D and E with those of factor 3. These associations suggest that site cluster A reflects the main path of the Kuroshio Current, cluster C-1 represents the open waters of the Pacific Ocean, and clusters C-2, D and E express susceptibility to carbonate dissolution at depths greater than 3000 m on the Ryukyu Trench slope. R-mode factor analysis using different loadings of factors 1 to 3 allows the 27 species and species groups to be classified into four groups A through D as follow: (1) Group A consists of taxa susceptible to carbonate dissolution such as the Globigerinoides ruber species group, G. sacculifer, etc. against group B which includes the Pulleniatina group, Neogloboquadrina dutertrei, Globorotalia tumida and G. menardii. Group B is dissolution resistant and also characterizes the Kuroshio Current. (2) Group C consists of Neogloboquadrina pachyderma (dextral), N. incompta and Turborotalia inflata, all indicative of “relatively cold” water. (3) Group D composed of Globigerina bulloides and Globigerinella calida suggests influence of coastal water invasion. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Three-dimensional inversion of gravity data from the Main Ethiopian Rift

The crustal thickness distribution beneath the Main Ethiopian Rift is determined using a 3-D inverse approach to gravity data interpretation. The depths to the crust-upper mantle interface form the inversion parameters. These initial model parameters are constrained with the results of the seismic refraction experiment of the region. The degree of ambiguity of the final model parameters is then quantified using a Q-mode factor analysis approach. The results of the modelling indicate a strong crustal attenuation zone (≤31 km) closely associated with the rifting of the graben and an abrupt fall of the Moho interface on either side of the rift (51 km) related to the formation of the western and southeastern plateaus. However, no indication of crustal separation is observed. The semi-quantitative ambiguity analysis reveals the association of the model parameters from the southeastern plateau with the strong ambiguity region. These model parameters represent the depths to the Moho interface where the seismic control is relatively less.

Quantification of aeolian dust (Kosa) contribution to the Japan Sea sediments and its variation during the last 200 ky.

In order to reconstruct past variations in the aeolian dust (Kosa) contribution to the Japan Sea, and to establish a direct link between terrestrial and marine climatic records, we have applied statistical procedures to distinguish and quantify detrital subcomponents within the detrital fraction of the late Quaternary hemipelagic sediments in the Japan Sea. Q-mode factor analysis with varimax and oblique rotation of the factors followed by multiple-regression analysis between mineral composition and factor loadings was conducted using six “detrital” elements. Four detrital subcomponents were defined, which are attributed to Kosa derived from “typical” loess, Kosa from “weathered” loess, and fine and coarse arc-derived detritus, respectively, based on comparisons with the chemical and mineral compositions of probable source materials. Using these detrital subcomponents, the variation in Kosa fraction was reconstructed for the last 200 ky. The results reveal millennial-scale as well as glacial-interglacial scale variations in Kosa contribution. Especially, millennial-scale variability of Kosa contribution suggests the presence of high frequency variation in summer monsoon precipitation in the central to east Asia during the last 200 ky.

Análise Fatorial (modo-Q) em estudos quantitativos de nanofósseis calcários do Quaternário Superior em um testemunho da Bacia de Campos, RJ - Brasil

In this paper a Q-mode factor analysis was carried out to study the late Quaternary calcareous nannofossils from core PC-01 (Campos Basin – Brazil). Using CABFAC computer program, two factors were obtained and explain 95,90%, the Factor 1, explain 93,69% and is dominated by speci Florisphaera profunda, wich is restricted to lower euphotic zone, this imply in deep nutricline and thermocline. Factor 2 explain 2,21% and is dominated by species Rabdosphaera clavigera and Gephyrocapsa oceanica, both ralated to shallow nutricline and thermocline. As the core is located mainly in a glacial sequence, it was possible to verify the changes of thermocline and nutricline in this core.

Radiolarian distribution in the water column, southern Gulf of California, and its implication in thanatocoenose constitution

The geographical and depth distributions of five radiolarian plankton assemblages, defined through Q-mode Factor Analysis of 24 plankton samples, demonstrate a direct correspondence to the distribution of oceanographic water masses in the southern Gulf of California. Two assemblages are associated exclusively with water masses of the mixed-layer, two represent only subsurface water masses, and one is important in both surface and subsurface environments. The Lithomelissa thoracites group and Peridium spinipes are predominant species in water that is formed at the surface of the Guaymas Basin and subsequently is subducted southward into the Carmen Basin. Plagiocantha panarium is the predominant species in upwelled surface water at the Carmen Basin, while Tetrapyle octhacanta and Botryostrobus scutum follow the incursion of the Subtropical Water Mass into the Gulf of California through the Pescadero and Farallon Basins. Druppatractus variabilis and Porodiscus sp. B occur conspicuously in the upper layer of the Pacific Intermediate Water between approximately 400 and 700 m water depth. Statistical correlation between plankton and sediment assemblages supports previous evidence that the radiolarian thanatocoenose in the Gulf of California is composed primarily of species from the surface mixed-layer. Two exceptions to this are observed in the data. First, the upwelling plankton assemblage was not well correlated to the sediment assemblage, and second, input to the sediment during glacial stages appears to be dominated by subsurface forms.

Characteristics of stone covers on the surface of basalt flows in arid, northeast Jordan

Variations in the stone covers on desert surfaces have implications for the operation of hydrological processes. Some recent attention has been given to the difficulties of identifying and quantifying relevant characteristics of stone covers. Investigation of how such characteristics vary in relation to geological and topographical controls are limited. Results are presented of a field study of the characteristics of stone covers on four lithologies in the late Tertiary to Quaternary basalt plateau of northeast Jordan. Marked variations occur in clast dimensions and the characteristics of sorting between lithologies which are likely to affect hydrological response. A more subtle control, relating to slope conditions, is superimposed on the lithological differences. R- and Q-mode factor analysis identifies groupings within the data, which demonstrate the distinctiveness of different lithologies. Characteristics of the stone covers on sites affected by human occupation are markedly different from undisturbed sites on the same lithology.

Calcium distribution in soils and stream sediments in Istria (Croatia) and the Slovenian littoral

For experimental geochemical mapping soil was sampled in 5×5 km regular grid in Istria and the Slovenian littoral (Croatia and Slovenia). The territory consists predominantly of karstified limestones and dolomites, and of flysch beds exposed in two basins, Istrian and Brkini. In addition to soil, stream sediment was also collected in the flysh area. Sampling was performed according to an analysis of variance design that permitted one to estimate the effects of the sample medium, geographic position, sampling error and analytical error. The analysis of variance of chemical variables indicated that soil and stream sediment as sampling media lead to similar results in producing geochemical maps. The largest differences with respect to the lithologic substrate of soil is indicated by calcium. As shown by the geochemical map, calcium in soil is high on the Istrian flysch beds, and low on limestones as well as on the flysch beds of the Brkini basin. The two soils also differ in mineralogy. The reason for this difference seems to lie in soil genesis on limestone and on flysch, and in the variable calcium content of flysch beds. The results of Q-mode factor analysis confirmed the adherence of soil and stream sediment of the two flysch basins to two differing groups. This difference was discovered by geochemical mapping. The hypothesis of differing calcium content in the rocks of the two basins was confirmed by the investigation of fresh and weathered rocks and soils in eight profiles sampled in the Brkini and Istrian flysch basin. It was found that the sandstone and calcarenitic samples from the Istrian basin contain an average factor of 3.5 more Ca than those of the investigated Brkini basin, and the samples of Istrian marls 4 times more Ca than those of the Brkini siltstones. Furthermore, the investigated weathered rocks and soils that originated from these rocks in the Istrian basin contain considerably more Ca than in the Brkini basin. In comparison with sandstone and siltstone samples of the Brkini basin, sandstone, calcarenite and marl samples of the Istrian flysch basin contain less clay minerals, quartz and feldspars and more calcite.

Transfer function between surface sediment diatom assemblages and sea-surface temperature and salinity of the Labrador Sea

Q-mode factor analysis (CABFAC) of 38 diatom species in 66 surface sediment samples from the Labrador Sea allowed the definition of six assemblages explaining 95.69% of the total variance. The first assemblage (40.12% of the total variance) is represented by Thalassiothrix longissima, a species characteristic of the Irminger Current and associated with the West Greenland Current. The second assemblage (34.52% of the total variance) is represented by Thalassiosira gravida (resting spores), a cold water species associated with the Labrador Current. A third assemblage (11.43% of the variance) represented by Chaetoceros spp. is concentrated in the northeastern section of the Labrador Sea and associated with upwelling and high productivity. The fourth, the fifth and the sixth assemblages, represented, respectively, by Coscinodiscus marginatus, Coscinodiscus oculus iridis, and Coscinodiscus divisus, and Nitzschia frigida, are less significant and account, respectively, for 4.95, 2.62 and 2.04% of the total variance. Transfer functions derived by relating factor assemblages to surface water temperature and salinity (August and February) give standard errors of estimate of ±0.93°C (August) and ±0.64°C (February) for temperature, and of ±0.58‰ (August) and ±0.45‰ (February) for salinity. High correlations between the measured and estimated parameters confirm the validity of the paleoecological equations for the reconstruction of the Labrador Sea paleoclimate.

Differentiating fluvio-marine depositional environments in the Nile Delta using textural and compositional components

Textural and coarse fraction compositional components are evaluated to distinguish samples from modern environments of the Nile Delta of Egypt. These environments include: river, coastal dune, accretion ridges, beach, neashore, lagoon and prodelta. In this study petrological variables (12 textural and 18 mineralogical, faunal and floral) were considered for each sample. Discrimination was achieved by using simple bar graphs of the raw data for each environment and Q-mode factor analysis. The factor analysis yielded four compositional assemblages: Factor 1 is dominated by terrigenous fine sand; factor 2 consists of biogenic mud; factor 3 contains terrigenous coarse and medium sands; and factor 4 comprises composite silty sand. Discrimination of the seven environments is generally good, with a lower resolution for beach, coastal dune and river sands. Having discriminating the examined environments using Q-mode factor analysis, a graphic model was constructed to help determine the origin of ‘unknown’ samples. As a test, this model is satisfactory in identifying and interpreting the origin of sediments of Holocene age from two additional cores recovered off the delta coast.

Palaeoceanography of the last glacial maximum in the eastern Indian Ocean: planktonic foraminiferal evidence

Palaeoceanographic conditions in the eastern Indian Ocean for the last ∼30 kyr are documented by means of planktonic foraminiferal analyses of 10 gravity cores. Quantitative foraminiferal analysis (%), Q-mode factor analysis, the modern analog technique (MAT) and oxygen-isotope analyses are used. A conspicuous increase during the last glacial maximum (LGM) of foraminiferal fragmentation resulting from a more productive Java upwelling system and/or a more corrosive Antarctic Intermediate Water (AAIW) was found at intermediate water depths (∼1000 m). Contrasting Q-mode factors based on foraminifera between today and the LGM suggest changes in the thermocline depth, sea-surface temperature (SST), upwelling, and the strength of both the Australasian Mediterranean Water (AAMW) and the Indian Central Water (ICW). The decrease in the percentage abundance of shallow-dwelling and symbiont-bearing planktonic foraminifera, the increase in percentage of the upwelling-related species Globorotalia cultrata and Neogloboquadrina dutertrei, and factor 3 (dominated by Globorotalia tumida and Globigerinella siphonifera) suggest a stronger Java upwelling system during the LGM. A steeper, steric latitudinal gradient (in the presence of a weak Leeuwin Current), and a geostrophic flow similar to today's is postulated for the LGM, and this must have prevented upwelling offshore Western Australia. Today's AAMW–ICW sharp front was weaker during the LGM when the AAMW was saltier, cooler, and nutrient richer and more similar to the ICW. During the LGM, a more gentle SST latitudinal gradient over the ∼16 to ∼23°S region contrasts with today's steeper conditions at the AAMW–ICW Front. Also, for the LGM, a nutrient-rich ICW may explain previously documented increases in mass accumulation rates of CaCO 3, organic carbon and benthonic foraminifera in a region where the nutricline was deep and within the lower euphotic zone.

Use of Factor Analysis to Study the Distribution of Metalliferous Bauxitic Tailings in the Seabed of the Gulf of Corinth, Greece

In 1994, a detailed marine environmental survey was carried out in surface sediments of the northern flank (Antikyra Bay) and the basin floor of the Gulf of Corinth. Metalliferous tailings (red-mud slurry) of a bauxite processing plant are discharged through a pipeline at a water depth of 100 m, in the Antikyra Bay, covering an area of 16 km2. The bauxitic tailings are detached from the main deposit at the outfalls, flow as turbidity currents downslope, and are redeposited on the basin floor of the Gulf of Corinth, where they cover an area of about 277 km2. One hundred sediment samples, that were collected from red-mud deposits and the surrounding natural sediments, were analyzed for Ag, Al, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Si, Ti, V, and Zn concentrations. Statistical analysis of the heavy metals concentrations using factor analysis allowed (i) an examination of the interrelations among metals and (ii) distinguishing possible sample groups on the basis of metal concentrations in order to study the mechanisms of transport of the red mud and the degree of mixing with natural sediments. Factor 1 (Al, Cr, Ti, Fe, Co, Ni, Pb, Ag, Hg, V, Cd, and Cu) and the positive pole of Factor 2 (Cu, Ag, Cd, and Hg) are “red-mud” factors, reflecting different metal behaviors, which are related to processes that take place during the transport and redeposition of the red mud. The negative poles of Factors 2 and 3 and the positive pole of Factor 4 are related to natural sediment supply processes. Q-mode factor analysis identifies three distinct sediment groups located in different areas, on the base of the degree of mixing of red mud with natural sediments.

Regional variability in ferromanganese nodule composition: northeastern tropical Pacific Ocean

Ferromanganese nodules are products of both direct and indirect precipitation in the marine environment; therefore, they potentially posses an important record of the oceanographic conditions under which they have grown. Previous attempts to extract useful paleoceanographic interpretations from ferromanganese nodules have been hampered by the scarcity of data and analytical inconsistencies, which make the separation of locally controlled versus regionally controlled variations in nodule composition difficult. Between 1978 and 1981, the Ocean Minerals Company (OMCO) conducted extensive surveys in the northeastern tropical Pacific Ocean. During this time the average bulk geochemistry of nodules from 4657 grab samples, collected from an area of approximately 1.5 million km 2, was determined using highly uniform and closely controlled analytical protocols. Because of its broad areal coverage, large sample size, and the consistency of the analytical techniques employed, this data set is ideally suited to quantitatively examine longstanding hypotheses concerning the factors that control the regional-scale variability of nodule compositions. A combination of geostatistical techniques have been employed to achieve this objective. The results of a Q-mode factor analysis of the geochemical data indicate that the nodules are composed of a two-component mixture of material acquired from both sediment and seawater sources via diagenetic and hydrogenetic accretionary processes, respectively. Linear modeling of these results determined that diagenetic accretion is the predominant accretionary processes in this region of the Pacific. Finally, a kriging analysis was employed to examine the spatial variability of nodule composition. Contour maps of the kriging results suggest that variations in primary productivity levels and sedimentation rates are the primary influences on the regional-scale variability of nodule composition, and that the influence of diagenetic accretion is maximally approaching the equatorial zone of high productivity. The nodules examined in this study are likely Oligocene to Miocene in age. The probable paleolocations of these nodules at that time, as determined by backtracking from the inferred northwesterly movement of the Pacific Plate, would still place the nodules well within the zone of equatorial high productivity. Consequently, while these nodules may have been subject to variations in the magnitudes of primary productivity and sedimentation rate during their active growth phase, the observed compositional trends suggest that the overall spatial pattern of productivity has remained essentially the same.

Paleoceanographic implications of Radiolaria in the southern Okinawa Trough over the last 20 000 years

Quantitative analyses have been carried out on radiolarians from 65 samples of Core 255 in the southern Okinawa Trough. The distribution of taxa and the results of Q-mode factor analysis show that during the last 20 000 years three radiolarian assemblages could be distinguished which can be correlated to high and low productivity levels indicated by the organic carbon content, radiolarian abundance and ratio of Nassellaria/Spumellaria in the sediment. TheTetrapyle quadriloba assemblage of thr last glaciation and deglaciation is associated with high productivity whereas the early HolocenePolysolenia spinosa and the middle and late HoloceneCarposhaera globosa assemblages correspond to low surface productivity. Meanwhile, the variations in the ratio of radiolarian fragments indicate higher SiO2 dissolution during the Holocene than during the last glacial stage.

Modeling Microstructural Heterogeneity in Materials by Using Q-Mode Factor Analysis

The basic objective of Q-mode factor analysis, a multivariate statistical technique based on the interrelation between samples, is classification of a suite of samples characterized by a large number of variables. The technique has been applied in modeling the microstructural heterogeneity present in a naturally occurring complex material. Significance of results is discussed with regard to the classification of multicomponent multiphase materials in general.

Abstract: Biostratigraphy and Paleoecology in High Energy, Bathyal Sedimentary Settings: Studies in the Main Pass area, Louisiana offshore, Gulf of Mexico

ABSTRACT The Main Pass area is an intersection of depositional environments, each of which leaves its own paleontologic imprint in the sedimentary record while mixing with and frequently obscuring others. High energy scouring, reworking, slumping and multiple sedimentary sources often obscure the succession of events that characterize the depositional and biostratigraphic history of the area. Paleontologic methods, such as water mass tracking and multivariate analysis of faunal succession, separate the biostratigraphic imprints of provenance and depositional energy as well as a history of water column changes that alter the depth associations of foraminiferal species. The separation of these factors allows for a minutely detailed understanding of sedimentary regimes and their dominance or recession over time, helping to characterize the types and qualities of potential reservoirs. Beneath regional unconformities in Main Pass representing the major datums are foraminiferal abundance peaks. The foraminiferal faunas of these events are, in part, characterized by cold-water benthics, usually assumed to be of deeper water affinities than those of the surrounding stratigraphic section. Another faunal characteristic of these events is the occurrence of cooler surface water planktonic species often associated with upwellings. The shoaling of deep currents prior or concorrent with lowstand is considered to be the cause for both of these characteristics. Extensive, longer term faunal changes are associated with probable changes in the source of deep and intermediate currents in the Gulf of Mexico. The interpretation of depositional energy regimes as determined by faunal response is tied directly to sedimentary setting, and yields more detailed information than estimates of paleobathymetry do. That the distribution of extant foraminifera was determined primarily by environmental energy was recognized by Uphaw and Stehli (1962) and Leutze (1972). Core data and interpretation of Main Pass seismic and electric logs were used to corroborate the environmental interpretations of the faunal abundances as described below. Figure 1 contains eight foraminifera abundance curves. These are derived from foraminiferal paleontologic data from an eastern Main Pass well spanning the early Pliocene and late Miocene. Curves 1 and 2 are total foraminiferal diversity; these predetermined statistics are provided for reference. Curve 8 is planktonic species abundance. Curves 2 through 7 are abundances for total foraminiferal faunal components separated by Q-mode factor analysis. They are arranged vertically from lowest amount of variance explained (3) to the greatest (7). The position of regional unconformities are indicated by arrows (^) at the base of curve 7. Curve 3 is dominated by species redeposited from the Florida platform. They are common in slumps and slides along the platform edge and in levee sediments along channels traced back to the platform. The contribution of this component to the sedimentary record is local and relatively constant, becoming obvious only when not overshadowed by riverine deposition. Curves 4 and 5 are regarded as representing redeposited species from riverine dominated and high energy neritic sediment sources, respectively. Curve 4 usually corresponds to the abundance of species carried by scouring sands of Mississippi River origin. The species of curve 5 are present in the scour surfaces of major unconformities and at the base of channels. The species represented by curves 6 and 7 are usually regarded as in situ, consisting respectively of moderately energy tolerant neritic species and energy intolerant species usually associated with bathyal water depths and conditions. These faunal components alternately represent, in relative abundance, the lowest energy sedimentation (condensed sections) or the highly productive periods prior to apparent lowstands. These are only a part of the depositional and paleoenvironmental features that can be segregated from high-energy sediments. Information on depositional pathways, freshwater incursion and other surface water environmental changes related to eustacy can be obtained by extension of the same statistical techniques.

Q-Analysis Techniques for Studying Communication Content

Q-analysis has proven a useful research methodology in a number of social science research areas for exploration of structures in human and social phenomena. Unrelated to either Q-mode factor analysis or the Q-sort technique, Q-analysis combines an anti-reductionist ethos with algebraic description. This paper addresses Q-analysis's potential contribution to content analysis of print communication. Twenty-seven news stories covering the “drug war” from the New York Times are analyzed to illustrate the Q-analysis approach and conceptual comparisons with traditional content analysis methodology are drawn. Advantages and disadvantages are evaluated. The report concludes that Q-analysis is a promising approach to content research that makes possible the mathematical expression of content properties beyond the reach of traditional content analysis methods.

Late quaternary benthic foraminifera and deep-water paleoceanography in the South China Sea

Recent and late Quaternary deep-sea benthic foraminifera in the South China Sea (SCS) have been quantitatively studied, in order to approach some disputable questions about the glacial deep circulation of the Pacific from the paleoceanographic records of a marginal sea, for example, whether or not there existed the North Pacific Deep Water (NPDW) during glacials. Based on the quantitative data of deep-sea benthic foraminiferal faunas from sixty-six surface sediment samples of the SCS, a Q-mode factor analysis indicates that the Globocassidulina subglobosa assemblage, the Astrononion novozealandicum and Bulimina aculeata assemblages and the Eggerella bradyi assemblage are associated with the Intermediate Water Mass (IWM), Deep Water Mass (DWM) and the deep water below CCD in the SCS, respectively. The factor assemblages resulted from surface sample data were then applied to the quantitative analysis of late Quaternary deep-sea benthic foraminifera in eight cores from the SCS and western Pacific. The results show a generally increased contribution of the DWM assemblage relative to that of the IWM assemblage during glacials, which implies that the influence of the DWM increased and that of the IWM decreased in the SCS and western Pacific. However, there were two major deep-water paleoceanographic changes during the late Quaternary: (1) The deep-sea carbonate dissolution of the SCS and western Pacific was intensified during δ 180 stages 4–5, evidenced by the higher arenaceous/calcareous ratios of benthic foraminifera and relative abundance of Eggerella bradyi. (2) The influence of the Pacific DWM above 2500 m greatly increased during the last glacial maximum (LGM), inferred from the increased abundances of the Pacific DWM benthic foraminiferal assemblage as compared to those of the Pacific IWM and Pacific Bottom Water Mass assemblages in the western Pacific. Particularly, the water in which Favocassidulina favus was distributed could not enter the SCS since the LGM. Meanwhile, the great changes had taken place in the DWM of the SCS during the LGM, reflected in the occurrence of a clearly cooled and ventilated DWM and the replacement of A. novozealandicum and B. aculeata assemblages by B. aculeata-Melonis barleeanum assemblage at water depths of 1000–2500 m. These significant changes during the LGM may be related to the formation of the NPDW