Strata In Terms Research Articles

Application of Neurofuzzy pattern recognition method in borehole geophysics

Geophysical data are specific physical responses of geological formations distributed over an area. These data are normally the physical parameters such as density, velocity, resistivity, susceptibility etc. of geological sources and hence bring a pattern of geological structures. It is conceived accordingly that this pattern recognition of such geophysical data will throw light on the spatial distribution and physical attributes of their geological sources. The well logging method considered as one of the geophysical method for the exploration of hydrocarbon, coal and base-metals, also has a strong role in finding the location and evaluation of geological resources.A novel approach known as Adaptive Neurofuzzy Inference System technique (ANFIS) is made to identify stratigraphy of Prydz Bay basin, east Antarctica. A geological stratum in terms of 1D model is made using datasets obtained from this area. The 1D model deduced as an ANFIS result is able to make geological sense of even additional thin sand sa...

Leaf Beetle Communities (Coleoptera: Chrysomelidae) of Two Mixed Forest Ecosystems Dominated by Pine—Oak—Hawthorn in Isparta Province, Turkey

Chrysomelid beetles inhabiting the herb, shrub and tree layers of two mixed forest ecosystems dominated by pine-oak-hawthorn were studied during April–October in 2005 and 2006 in Isparta province, Turkey. The leaf beetles of both sites were investigated in terms of species composition, dominance structure and vegetation preference. Frequency values and host plants were also provided for some species. A total of 127 Chrysomelidae species belonging to ten subfamilies were collected. Species composition similarity between the herb and tree layers was 3% at both sites, while similarity between the shrub and tree layers was 25% at site I and 44% at site II. In terms of vegetation structure, the herb layers of the two sites shared 60% of their chrysomelid species, the shrub layers shared 44% and the tree layers shared 50%, a result also reflected in a PCA analysis. The herb layer was the most diverse vegetation stratum in terms of leaf beetle diversity, and it appears that vegetation cover is the main factor in...

Jacobi inversion on strata of the Jacobian of the C rs curve y r =f(x)

By using the generalized sigma function of a C rs curve y r =f(x) , we give a solution to the Jacobi inversion problem over the stratification in the Jacobian given by the Abel image of the symmetric products of the curve. We show that determinants consisting of algebraic functions on the curve, whose zeros give the Abelian pre-image of the strata, are written by ratios of certain derivatives of the sigma function on the strata. We also discuss the order of vanishing of abelian functions on the strata in terms of intersection theory.

Investigation of catastrophic ground collapse in Xingtai gypsum mines in China

Mining-induced ground collapse brings about harmful results to environment, fatality and property losses. In particular cases, there is lack of forewarning that a catastrophic collapse will occur in minutes. Therefore, a better understanding of the behavior and stability of ground strata in mining is of significant importance to improve mining design, to monitor the situation of the rock strata and, if it is possible, to forecast the catastrophic ground movement. In the presented work, a large-scale ground collapse in the Xingtai gypsum mines has been investigated through site measurement together with theoretical and numerical analysis. The collapse induced a strong air shock and severe failure of rock strata. From the technical points of view, the investigation covers the calculation of air shock intensity, the analysis of the pillar instability and the fracture process in the roof strata in terms of a plate seated on an elastic foundation. A few mechanical models have been proposed and discussed in detail. Finally, the essential and key factors that resulted in the catastrophe are elaborated by means of comprehensive studies.

Prostate cancer disease-free survival after radical retropubic prostatectomy in patients older than 70 years compared to younger cohorts

Objectives To evaluate the feasibility of radical retropubic prostatectomy (RRP) as an option for treating men older than 70 years with organ confined prostate cancer and to compare biochemical progression-free survival with younger cohorts. Materials and Methods A total of 689 consecutive patients who were treated with RRP from 1994 to 2002 for clinically localized prostate cancer were categorized into 3 different age groups: younger than 50 years (n = 49), 50–70 years (n = 601), and older than 70 years (n = 39). Patients older than 70 years were healthy individuals for their age. Preoperative and postoperative cancer-specific characteristics were compared among these 3 groups. Results There was no statistical significant difference among the 3 age strata in terms of clinical parameters (prostate-specific antigen, Gleason score, clinical stage, percent and number of positive biopsy cores) and pathologic findings (surgical margin, lymph node status, extracapsular extension, lymphovascular invasion, and pathologic Gleason score). The rate of seminal vesicle invasion and prostate volume increased with advancing age ( P = 0.034 and P < 0.001). In multivariate logistic regression analysis, age was not associated with seminal vesicle invasion. The 5-year prostate-specific antigen progression-free estimates for patients younger than 50, 50–70, and older than 70 years were 82% (95% confidence interval [CI] 69% to 96%), 82% (95% CI 78% to 86%), and 65% (95% CI 43% to 86%), respectively ( P = 0.349). The overall and cause-specific mortalities were not different. Conclusions RRP could be considered a standard treatment option in men older than 70 years with localized prostate cancer. Further studies are necessary to assess the survival benefit and health-related quality of life after radical prostatectomy versus watchful waiting in patients older than 70 years.

Planktonic Microbial Communities Associated with Fracture-Derived Groundwater in a Deep Gold Mine of South Africa

The vertical distribution and function of terrestrial planktonic microbial communities at depths greater than 600 m remain poorly established. Culture-independent methods using 16S rRNA genes and geochemical approaches were employed to investigate the heterogeneity and potential function of microbial communities residing within fractures at 0.7 to 1.4 kilometers below land surface of Beatrix Au Mine, South Africa. The salinity (26 to 47 mM Cl−), temperature (33 to 40°C) and age (1 to 5 Ma) of these fracture water increased with depth. The δD and δ18O values of fracture water ranged from −44 to −39‰ and from −7 to −4‰ VSMOW, respectively, and exhibited a mixing trend with fracture water collected from the same mine in a previous study where isotopic signatures were indicative of hydrothermal origin. Fracture water from Beatrix Mine was distinct from the groundwater in the overlying Karoo sedimentary strata in terms of its Cl−, He and CH4 concentrations, and its δD and δ18O signatures and from Vaal River (source of service water) in terms of its δD and δ18O signatures. The differences constrain the maximum amount of mixing with service water or shallow groundwater to be less than 4%. The 16S rDNA analyses revealed diverse and numerous novel 16S rRNA genes affiliated with Proteobacteria, Firmicutes, Nitrospira, Chlorobi, Thermus, Candidate Division OP3 and Euryarchaeota. The proportion of each phylum in clone libraries varied markedly among samples and suggests km-scale, spatial heterogeneity in community structures. Potential metabolisms inferred from the presence of 16S rRNA genes are generally consistent with estimates of the available free energy.

Pairwise comparisons for proportions estimated by pooled testing

When estimating the prevalence of a rare trait, pooled testing can confer substantial benefits when compared to individual testing. In addition to screening experiments for infectious diseases in humans, pooled testing has also been exploited in other applications such as drug testing, epidemiological studies involving animal disease, plant disease assessment, and screening for rare genetic mutations. Within a pooled-testing context, we consider situations wherein different strata or treatments are to be compared with the goals of assessing significant and practical differences between strata and ranking strata in terms of prevalence. To achieve these goals, we first present two simultaneous pairwise interval estimation procedures for use with pooled data. Our procedures rely on asymptotic results, so we investigate small-sample behavior and compare the two procedures in terms of simultaneous coverage probability and mean interval length. We then present a unified approach to determine pool sizes which deliver desired coverage properties while taking testing costs and interval precision into account. We illustrate our methods using data from an observational HIV study involving heterosexual males who use intravenous drugs.

Biology and fishery of Eledone cirrhosa in the Ligurian Sea

Biological information for Eledone cirrhosa has been reassessed through two series of trawls in the framework of the Research Projects MEDITS (summer) and GRUND (autumn) over a 10-year period of surveys in the Ligurian Sea. This information covers aspects such as life span and growth and mortality rates. The sum of samples obtained in the two different seasons allowed the analysis of consistent length frequency distributions and resulted in distinguishing recruits/juveniles from adults of two different ages, i.e. E. cirrhosa is a relatively long living cephalopod, whose reproduction occurs in the second or third year of life. By sampling in different bathymetric strata, different densities on shelf and slope fishing grounds were measured and their displacements with changing season were monitored. The most important stratum in terms of summer densities was in the range 100–200 m depth, which includes the shelf edge, at 150 m. In a relatively narrow strip of seabed, covered by the shelf-edge detritic assemblage and adjacent muddy bottom assemblage VTC (80–150 m), the recruitment of E. cirrhosa occurs from January onwards, while till recent times a specific trawling targeting juveniles used to be carried out in late spring and summer months. In autumn E. cirrhosa is mainly concentrated in shallower waters where trawling activity does not specifically target this species. Trends in numbers and biomass derived by the two series of surveys, and in particular those during autumn series have revealed a significant decrease over the studied time interval. Therefore, the possible relationship between large-scale environmental factors and/or exploitation, was investigated and a positive relationship between summer biomass and winter NAO index was found, even if the cause of such relationship remains unexplained. However, trends of E. cirrhosa landings reported in other studies of the north-western Mediterranean resulted in a similar relationship, thus reinforcing the hypothesis of climatic factors influencing the success of the fishery of this biological resource. A tentative stock assessment, based on relative yield-per-recruit functions, taking into account the two different lengths at first capture and corresponding to mesh sizes of 20 or 40 mm (juveniles and adults nets), showed overexploitation and underexploitation, respectively. A preliminary study of density indices by vital phase also demonstrated a correlation between summer spawners and autumn juveniles of the following year, thus providing evidence of a stock–recruitment relationship.

Europe from the Bottom: Assessing Personal Gains and Losses and its Effects on EU Support

Numerous authors have highlighted utilitarian considerations as sources of public support for the European Union, suggesting that support results primarily from cost-benefit calculations of the gains and losses associated with integration. Benefits accrue, not only to different member states, but also to individuals. Within this discussion it is often suggested that the gains and losses are unevenly distributed across social groups, with the higher status groups being privileged and the lower status groups disadvantaged. This paper challenges arguments that assume a clear division between lower social strata and higher social strata in terms of winning and losing in Europeanization; it looks more closely at how Europeans rate the integration process as it affects them personally, and how this influences their support for integration. The results show that socio-economic characteristics cannot fully explain people's perceptions of being winners or losers, and a large proportion of EU citizens do not consider themselves either winners or losers. The paper also demonstrates that the winner/loser self-characterization is indeed a major determinant of support for the EU, but that it only partly coincides with people's socio-economic position.

Manifold-theoretic compactifications of configuration spaces

We present new definitions for and give a comprehensive treatment of the canonical compactification of configuration spaces due to Fulton–MacPherson and Axelrod–Singer in the setting of smooth manifolds, as well as a simplicial variant of this compactification initiated by Kontsevich. Our constructions are elementary and give simple global coordinates for the compactified configuration space of a general manifold embedded in Euclidean space. We stratify the canonical compactification, identifying the difieomorphism types of the strata in terms of spaces of configurations in the tangent bundle, and give completely explicit local coordinates around the strata as needed to define a manifold with corners. We analyze the quotient map from the canonical to the simplicial compactification, showing it is a homotopy equivalence. Using global coordinates we define projection maps and diagonal maps, which for the simplicial variant satisfy cosimplicial identities.

Towards an intersection theory on Hurwitz spaces

Moduli spaces of algebraic curves are closely related to Hurwitz spaces, that is, spaces of meromorphic functions on curves. All of these spaces naturally arise in numerous problems of algebraic geometry and mathematical physics, especially in connection with string theory and Gromov-Witten invariants. In particular, the classical Hurwitz problem of enumerating the topologically distinct ramified coverings of the sphere with prescribed ramification type reduces to the study of the geometry and topology of these spaces. The cohomology rings of such spaces are complicated even in the simple case of rational curves and functions. However, the cohomology classes most important for applications (namely, the classes Poincaré dual to the strata of functions with given singularities) can be expressed in terms of relatively simple “basic” classes (which are, in a sense, tautological). The aim of the present paper is to identify these basic classes, to describe relations between them, and to find expressions for the strata in terms of them. Our approach is based on Thom's theory of universal polynomials of singularities, which has been extended to the case of multisingularities by the first author. Although the general Hurwitz problem still remains open, our approach enables one to achieve significant progress towards its solution and an understanding of the geometry and topology of Hurwitz spaces.

Ancestor ideals of vector spaces of forms, and level algebras

Let R= k[ x 1,…, x r ] denote the polynomial ring in r variables over a field k, with maximal ideal M=( x 1,…, x r ), and let V⊂ R j denote a vector subspace of the space R j of degree- j homogeneous elements of R. We study three related algebras determined by V. The first is the ancestor algebra Anc(V)=R/ V whose defining ancestor ideal V is the largest graded ideal of R such that V∩M j=(V) , the ideal generated by V. The second is the level algebra LA( V)= R/ L( V) whose defining ideal L( V), is the largest graded ideal of R such that the degree- j component L( V)∩ R j is V; and third is the algebra R/( V). We have that L(V)= V+M j+1 . When r=2 we determine the possible Hilbert functions H for each of these algebras, and as well the dimension of each Hilbert function stratum. We characterize the graded Betti numbers of these algebras in terms of certain partitions depending only on H, and give the codimension of each stratum in terms of invariants of the partitions. We show that when r=2 and k is algebraically closed the Hilbert function strata for each of the three algebras attached to V satisfy a frontier property that the closure of a stratum is the union of more special strata. In each case the family G( H) of all graded ideals of the given Hilbert function is a natural desingularization of this closure. We then solve a refinement of the simultaneous Waring problem for sets of degree- j binary forms. Key tools throughout include properties of an invariant τ( V), the number of generators of V⊂k[x 1,x 2] , and previous results concerning the projective variety G( H) in [Mem. Amer. Math. Soc., Vol. 10 (188), 1977].

Devonian–Early Carboniferous miospore biostratigraphy of the Amazon Basin, Northern Brazil

A miospore biozonation, including 17 new interval zones, is proposed for Devonian–Early Carboniferous stratigraphic sections in the Amazon Basin. It results from a detailed review of the coeval miospore assemblages and biohorizons in the basin. The combined use of selected Euramerican and Western Gondwanan forms as zonal and characteristic taxa permits accurate subdivision, dating and correlation of Amazon Basin palyniferous strata in terms of equivalent miospore zones of Western Europe and the Old Red Sandstone Continent. The miospore data provide new insights into such varied issues as e.g. the age and stratigraphic relationships of regional rock units, the detection and dating of intervening hiatuses, condensed sedimentary sections, anoxic phases, and resedimentation cycles. Although primarily devised to serve as a regional biozonation, the scheme presented here has a unifying character because it can be applied to other Paleozoic basins in Brazil and Western Gondwanan regions where similar miospore successions are documented. A miospore assemblage zone recently described for the early Late Carboniferous interval of the Amazon Basin is also partly reviewed and integrated with the new biozonation for the older sections.

Tree-root systems and herbaceous species-characteristics under tree species introduced into grazing lands in subhumid Cameroon

The effect of tree species on the characteristics of the herbaceous stratum, during the first five years of a fallow, was evaluated in the North of Cameroon (average annual temperature 28.2 °C, total annual rainfall 1050 mm). Treatments included a natural grazed herbaceous fallow, a natural ungrazed herbaceous fallow and three planted tree fallows (Acacia polyacantha Willd. ssp. campylacantha (Hochst. ex A. Rich.), Senna siamea Lam. and Eucalyptus camaldulensis Dehnh.), which were protected against grazing. Because tree species influenced light interception in different ways, as well as having different root patterns, they had different effects on the herbaceous stratum in terms of species composition and biomass. The grazed herbaceous fallow maintained the greatest species richness. Protection against grazing or the introduction of tree species associated with the absence of grazing induced both a progressive evolution to a particular species composition. The ungrazed herbaceous fallow consisted mainly of Andropogon gayanus Kunth, which provided the greatest biomass (8 t dry matter ha–1 at the end of the fallow period). E. camaldulensis provided little shade and the lowest fine root mass in the top layer allowing the growth of A. gayanus and thus a greater herbaceous biomass (3.5 t DM ha–1) than that found under the other tree species. Under the heavy shade of A. polyacantha, the herbaceous stratum consisted mainly of annual Pennisetum spp. (2.2 t DM ha–1) and showed the greatest N concentration (1.3%), probably due to N2 fixation by the tree species. After the fourth year, despite the relatively open tree canopy, S. siamea, which showed the highest fine root mass, had a strong depressive effect on the herbaceous stratum.

Some Design Problems in Crop Experimentation. I. The Use of Blocks

SUMMARYField experiments are commonly designed in blocks and there are sound reasons for using them, for example, control of unwanted environmental differences and administrative convenience. If used, they should be chosen to correspond to perceived differences in the site or to simplify farm operations and not merely to conform to statistical desiderata. Thus, it is not essential that each must contain one plot for each treatment, though there are advantages if they do. Some of the consequences of using other block sizes are examined, it being borne in mind that modern computer packages will perform most of the tiresome arithmetic. The effectiveness of blocks is considered and it is noted that they sometimes do harm rather than good. The analysis of variance is explained in terms of strata as used in many modern computer programs and is extended to include the recovery of information and resolvability. Recommendations are made as to randomization.

The summer zooplankton community at South Georgia: biomass, vertical migration and grazing

Zooplankton abundance and biomass were determined during January 1990 at two stations to the north-west of South Georgia using a Longhurst Hardy Plankton Recorder (LHPR). At both shelf and oceanic station sites, zooplankton biomass, (excluding Euphausia superba), was found to be ca. 13 g dry mass m−2. Copepods and small euphausiids dominated the catches. These estimates are over 4 times higher than values generally reported for the Southern Ocean and may reflect firstly, the high productivity of the study area, secondly, the time of year, summer, when biomass for many species is maximal, and thirdly, the high sampling efficiency of the LHPR. Principal components analysis disclosed similarities and differences between adjacent depth strata in terms of abundance, biomass and species composition. At both stations most variability occurred in the mixed layer (0–60 m) and thermocline (60–120 m) with depth horizons below this being more homogeneous. Diel migrations were observed for most taxa with abundance increasing in the mixed layer at night. At the oceanic station, species and higher taxa belonging to the mesopelagic community were generally well spread throughout this domain and, with the exception of Pleuromamma robusta and Metridia curticauda, showed little evidence of migration. The grazing impact of the epipelagic community (copepods and small euphausiids) was estimated to remove 3–4% of the microbial standing stock day−1 and a conservative 25% and 56% of daily primary production at the oceanic and shelf stations respectively.

The spectrum of the variable planetary nebula IC 4997

The compact, dusty, presumably young planetary nebula (PN) IC 4997 has been studied extensively since the variability of the lambda 4363/lambda 4340 ratio was established in 1956. Since 1938, other nebular lines have shown changes. IC 4997 is also unique because of the great density range revealed by its spectrum which goes in excitation from Mg I to (Ar IV). We present a detailed listing of spectral lines from 360 to 1005 nm. The diagnostic diagram shows that the spectrum can be interpreted only in terms of strata with a huge density gamut. Essential spectral features can be reproduced approximately by a model consisting of a geometrically thin shell of density around 10(exp 7) atoms cm(exp -3), surrounded by a much larger shell with a density of about 10(exp 4) atoms cm(exp -3). The actual, certainly more complex structure can be evaluated only when high resolution spatial imaging is at hand. The usual method of getting abundances from N(ion)/N(H(+)) and ionization correction factors (ICFs) cannot be applied here. It is argued that a reasonable theoretical model that represents the spectrum provides a valid initial approximation to nebular abundances. We propose that the chemical composition of IC 4997 does not differ greatly from that of the Sun. The finally adopted model suggests that the ejection of the material destined to form the inner shell occurred between 1900 and 1960, but observational evidence of such an ejection event is lacking. Perhaps the shell was accelerated. A need for further study is emphasized, especially the role of dust which appears to contribute 2% of the total mass. More attention to this object is recommended. An accurate measurement of its distance is especially desirable.

Open and filled karst features on the Cayman Islands: implications for the recognition of paleokarst

The dolostones of the Oligocene–Miocene Bluff Formation on the Cayman Islands are characterized by well-developed surficial, interface, and subsurface karst features that are open or filled with speleothems and sediment.Some of the open caves show evidence of a minimum of two stages of development related to dissolution in the phreatic zone and the vadose zone. The development of speleothemic formations (e.g., stalactites, stalagmites, columns) is limited in some caves but extensive in others. Some of the caves have limited amounts of sediment on their floors. In these caves, the speleothems and sediments are still formed of CaCO3 and thus contrast sharply with the dolostone of the Bluff Formation in which they occur. Some of the joints, sinkholes, and caves are filled with breccia, caymanite, terra rossa, terra rossa breccia, pisolitic limestone, and speleothems. Although filled, such karst features are analogous to the open karst features that occur elsewhere on the islands. The filling of joints, sinkholes, or caves is not directly related to the age of the karst development, since caves of the same age may be open or filled. This suggests that local conditions, such as the availability of sediment or the nature of the waters flowing through the caves, played an important role in determining whether a karst feature is filled.Surficial karst features have a low preservation potential, whereas interface and subsurface karst features have a high preservation potential in some circumstances. In the case of sinkholes this assumes that later transgressions did not remove the upper part of the rock body that contained the filled sinkholes. For caves this assumes that they were filled with speleothems and sediment prior to their reaching such a size that collapse of the overlying strata occurred because of the lack of support. If collapse occurs, the presence of caves can only be inferred from the resultant collapse breccias. A potentially valuable criterion for the recognition of paleokarst may lie in the fact that the rocks filling open karst features (e.g., joints, sinkholes, caves) may contrast sharply with the host strata in terms of both lithology and age.

Zeros of covariant vector fields for the point groups : invariant formulation

All finite as well as infinite (matrix) point subgroups of full orthogonal groups in two and three dimensions are considered. For each point group a polynomial integrity basis for invariants and the basic polynomial vector fields are first given. Then, the strata are defined via equations and inequalities involving the integrity basis. Finally, equations for zeros of a covariant vector field are given on each stratum in terms of the integrity basis, which appears via coefficients in the expansion of the vector field on the vector-field basis. All the results are tabulated and an illustration using the cubic group is presented. Mathematical background sufficient for extensions of the results is also given.

Problematics in Stratum Consistency and Stratum Formation: An Australian Example

Questions relating to the consistency of the stratification order can be posed at the level of social aggregates as well as at the individual level. This paper draws on Australian socioeconomic data to illustrate issues involved in defining relatively homogeneous social strata in terms of commonly occurring status profiles and in exploring the effects of stratum characteristics such as degree of stratum homogeneity and stratum attribute consistency. Positional awareness, defined in terms of class identification and voting behavior, is examined in relation to the contextual variables of stratum homogeneity and stratum attribute consistency, which show weak effects once the average level of socioeconomic status of different strata is taken into account. The low salience of such contextual variables is explained partly by relatively high stratum permeability, reflected in high rates of father-to-son mobility, and partly by the difficulty of establishing that the strata as defined are perceived as naturally occurring groups.