Single Log Research Articles

Effect of spatial scale on habitat use of Bolitotherus cornutus (Coleoptera: Tenebrionidae)

AbstractThe habitat of Bolitotherus cornutus Panzer consists primarily of sporophores of the shelf fungus Fomes fomentarius (L.:Fr.) J. Kickx fil. Each sporophore is discrete and often several are present on a single dead log or standing snag, especially of paper birch (Betula papyrifera Marsh.). An exploratory approach was used to examine habitat use at three scales (the single sporophore, a single log supporting up to several sporophores, and a group of logs supporting sporophores) by modeling incidence of adult B. cornutus. Sporophore volume and decay were important for the beetles at all scales. Patches containing a variety of states of sporophores from alive to dead and decomposing are probably most suitable to B. cornutus. Results are compared with those for the related European beetle Bolitophagus reticulatus (L.), which is similar ecologically and also occupies F. fomentarius sporophores.

Study of a breast tumor extraction algorithm for three-dimensional ultrasound images, using multiple space differentiation filters: Automated breast tumor extraction algorithm with improved accuracy

The system to be developed in the present study will enable us to extract the tumor region automatically from three-dimensional ultrasonic images of the breast, and differentiate benign from malignant tumors by using the characteristics of their surface form. In application of such a system, the accuracy of diagnosis greatly depends on its ability to extract tumor automatically. We developed an algorithm for determination of the tumor region using fuzzy reasoning, that is, we classified each voxel of three-dimensional images as “tumor,” “normal tissue” and “boundary,” and, using relaxation techniques to resolve regional contradictions, made final decisions as to the tumor region. It must be noted that, according to this algorithm, a three-dimensional the space differentiation filtering automatically generates a membership function for the fuzzy reasoning. Previous attempts of extracting tumor used a single LoG filter as the space differentiation filter. We recently developed a method which can cope with diverse ultrasound images more flexibly. With this new method, multiple DoG filters with varying characteristics are prepared in addition to the LoG filter, and the optimum one is selected from multiple extraction results. The introduction of this method improved the accuracy of extraction.

Combined contributions of streptolysin O and streptolysin S to virulence of serotype M5 Streptococcus pyogenes strain Manfredo.

Streptolysin O (SLO) and streptolysin S (SLS) are potent cytolytic toxins produced by almost all clinical isolates of group A streptococci (GAS). Allele-replacement mutagenesis was used to construct nonpolar (in-frame) deletion mutations in the slo and sagB genes of the serotype M5 GAS strain Manfredo, producing isogenic single and double SLO- and SLS-defective mutants. In contrast to recent reports on SLS-defective insertion mutants (I. Biswas, P. Germon, K. McDade, and J. Scott, Infect. Immun. 69:7029-7038, 2001; Z. Li, D. Sledjeski, B. Kreikemeyer, A.Podbielski, and M. Boyle, J. Bacteriol. 181:6019-6027, 1999), none of the mutants described here had notable pleiotropic effects on the expression of other virulence factors examined. Comparison of isogenic parent and mutant strains in various virulence models revealed no differences in their abilities to multiply in human blood or in their 50% lethal doses (LD(50)s) upon intraperitoneal infection of BALB/c mice. A single log unit difference in the LD(50)s of the parent and SLS-defective mutant strains was observed upon infection by the subcutaneous (s.c.) route. Comparisons over a range of infective doses showed that both SLO and SLS contributed to the early stages of infection and to the induction of necrotic lesions in the murine s.c. model. Individually, each toxin made an incremental contribution to virulence that was not apparent at higher infective doses, although the absence of both toxins reduced virulence over the entire dose range examined. Interestingly, in some cases, the contribution of SLO to virulence was clear only from an analysis of the double-mutant strain, highlighting the value of not confining virulence studies to mutant strains defective in the expression of only single virulence factors.

Regional and local population structure of the pioneer wood-decay fungus Trichaptum abietinum

The population structure of 11 Fennoscandian geographic populations of the pioneer wood-decay basidiomycete Trichaptum abietinum was assessed with PCR-RFLPs, intersequence simple repeats (ISSRs) and mating studies. The three codominant PCR-RFLP markers (1) internal transcribed spacer 2 (nrDNA), (2) glyceraldehyde-3-phosphate dehydrogenase and (3) translation elongation factor 1α showed that genotype distributions in most cases (94%) agreed with Hardy-Weinberg expectations and that random association of alleles occurred across loci. The molecular data suggest that T. abietinum is a highly outcrossing fungus that regularly proliferates and spreads by sexual spores. Interstock mating reactions suggest a high number of mating factors among individuals and that biological barriers to gene flow are nonexistent in the region. The three PCR-RFLP loci gave an overall FST = 0.03, indicating a low level of genetic differentiation and presumably high gene flow among the geographic populations. The ISSR markers revealed no systematic substructuring and the among-population variance component was low (6.1%) in AMOVA. However, all PCR-RFLP and most ISSR markers (7/12) showed significant deviation from the null hypothesis of an even distribution of allele frequencies across the 11 geographic populations. Allele frequencies varied in an apparently random manner, suggesting that genetic drift might be an important structuring factor in T. abietinum. The spatial small-scale distribution of heterokaryons on three selected substrate units (logs) showed that most isolates represented discrete individuals and that a number of genets (19) may occupy a single log. The small-scale genotype distributions (within logs) were in agreement with panmictic Hardy-Weinberg expectations.

Neural Network Predictions of Human Psychological Perceptions of Clothing Sensory Comfort

The objective of this'paper is to investigate the predictability of clothing sensory comfort from psychological perceptions by using a feed-forward back-propagation net work in an artificial neural network (ANN) system. In order to achieve the objective, a series of wear trials is conducted in which ten sensory perceptions ( clammy, clingy, damp, sticky, heavy, prickly, scratchy, fit, breathable, and thermal) and overall clothing comfort ( comfort) are rated by twenty-two professional athletes in a controlled la ratory. They are asked to wear four different garments in each trial and rate the sensations above during a 90-minute exercising period. The scores are were input into five different eed-forward back-propagation neural network models, consisting of six different numbers of hidden and output transfer neurons. Results showing a good correlation between redicted and actual comfort ratings with a significance of p < 0:001 for all five models indicate overall comfort performance is predictable with neural networks, particularly models with log sigmoid hidden neurons and pure linear output neurons. Models with a single log sigmoid hidden layer with fifteen neurons or three hidden layers, each with ten log sigmoid hidden neurons, are able to produce better predictions than the other models for is particular data set in the study.

Statistical and probabilistic modelling of uniaxial creep life of a Ti-6246 alloy

Repeat data on a Ti-6246 alloy at 773 K and 580 MPa provided a unique opportunity to identify stochastic creep properties and to use this information to build a probabilistic creep damage assessment for this alloy. The stochastic nature of creep properties both under a single test condition (using a generalised gamma distribution) and under various test conditions (by combining this distribution with the Monkman–Grant relationship) were identified. Under the single test condition log failure times had a distribution skewed to the right and log minimum creep rates had a distribution skewed to the left. Over various test conditions a failure time distribution similar to the Weibull distribution was most supported by the data. The observed log time to failure at 480 MPa was well within the extrapolated 95% confidence limits obtained from the Monkman–Grant model. Uncertainty about the exact distributional form increased this 95% confidence limit.

Rapid automated antimicrobial susceptibility testing of Streptococcus pneumoniae by use of the bioMerieux VITEK 2.

The VITEK 2 is a new automated instrument for rapid organism identification and susceptibility testing. It has the capability of performing rapid susceptibility testing of Streptococcus pneumoniae with specially configured cards that contain enriched growth medium and antimicrobial agents relevant for this organism. The present study compared the results of testing of a group of 53 challenge strains of pneumococci with known resistance properties and a collection of clinical isolates examined in two study phases with a total of 402 and 416 isolates, respectively, with a prototype of the VITEK 2. Testing was conducted in three geographically separate laboratories; the challenge collection was tested by all three laboratories, and the unique clinical isolates were tested separately by the individual laboratories. The VITEK 2 results of tests with 10 antimicrobial agents were compared to the results generated by the National Committee for Clinical Laboratory Standards reference broth microdilution MIC test method. Excellent interlaboratory agreement was observed with the challenge strains. The overall agreement within a single twofold dilution of MICs defined by the VITEK 2 and reference method with the clinical isolates was 96.3%, although there were a number of off-scale MICs that could not be compared. The best agreement with the clinical isolates was achieved with ofloxacin and chloramphenicol (100%), and the lowest level of agreement among those drugs with sufficient on-scale MICs occurred with trimethoprim-sulfamethoxazole (89.7%). Overall there were 1.3% very major, 6.6% minor, and no major interpretive category errors encountered with the clinical isolates, although >80% of the minor interpretive errors involved only a single log(2) dilution difference. The mean time for generation of susceptibility results with the clinical isolates was 8.1 h. The VITEK 2 provided rapid, reliable susceptibility category determinations with both the challenge and clinical isolates examined in this study.

Gas/solid partitioning of semivolatile organic compounds (SOCs) to air filters. 1. Partitioning of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and polycyclic aromatic hydrocarbons to teflon membrane filters

Gas/particle distributions of semi-volatile organic compounds (SOCs) in the atmosphere are often measured using filter/sorbent samplers. Unfortunately, the adsorption of gaseous SOCs onto a filter can cause positive biases in the measured particle-phase concentrations, and negative biases in the measured gas-phase concentrations. In order to permit estimation of the magnitudes of these errors when Teflon membrane filters (TMFs) are used, surface-area-normalized gas/Teflon partition coefficient ( K p,s) values were measured for a range of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polycyclic aromatic hydrocarbons (PAHs). Sorption isotherms were linear over three orders of magnitude. A 10° change in temperature ( T) caused the K p,s values to decrease by factors of 2.4–3.4. Changes in relative humidity (RH) between 21 and 52% did not affect the measured K p,s values. The dependence of the partitioning on the sub-cooled liquid vapor pressures of the subject compounds was investigated. Within each of the three individual compound classes, plots of log K p,s vs. log p L o were linear with slopes of approximately −1. The pooled data for the three compound classes yielded a single log K p,s vs. log p L o plot for 25°C that was correlated nearly as well ( r 2=0.96) as the plots for the individual compound classes ( r 2≈0.95). Since backup TMFs used in filter/sorbent sampling in urban areas yielded the same K p,s values as did clean TMFs, assessment of the magnitude of the gas adsorption artifact for TMFs can be carried out using K p,s values obtained with clean and/or ambient backup TMFs.

Well log stacking: a new technique to improve laterial prediction and sequence stratigraphic interpretation with wireline data

The correlation of wireline (well log) data forms an essential part of the interpretation of geological strata in sedimentary basins. The technique usually involves matching by eye the log curves produced from digitally sampled data in one well with those from one or more adjacent wells. Correlation is used primarily to access the lateral extent of rock bodies in the subsurface. However, it is a highly subjective process and is hampered by the difficulty in visually discriminating between non-geological noise, local geological trends and regional geological trends when comparing a number of logs. Variations in the thickness of an interval or differences in the data acquisition between wells compound these problems. Correlation is also constrained by the number and spacing of the wells in question. Thus it is hard to determine what is happening between widely separate wells whilst it is difficult to interpret more than a few log curves at one time due to their complexity. The solution is typically to concentrate on only a few obvious features such as a minimum or maximum peak or the diagnostic response of a specific rock type and to make some simple assumptions as to the lateral extent of other features. Even where additional geological data such as biostratigraphic or core information are available, it is often impossible to be sure that a log pattern in one well is not coincidentally similar to that in another well and regional geological trends will often be disguised by higher amplitude, shorter wavelength local variations. As a consequence of the problems mentioned above, the methodology used in correlating well logs is typically rather arbitrary and is unlikely to use all the data to full advantage. Hence it is difficult to objectively evaluate the validity or confidence level in correlations when assessing, for example, whether reservoirs are likely to be connected across a field or what the chance are of finding a known reservoir in a new well. The subject of this paper is a new automated tool which aims to improve on traditional manual correlation techniques by incorporating all equivalent data from every relevant well into a single log curve. The process suppresses the effect that local variations have on the log signal and enhances the regional response.

98/04008 Combustion of a single wood log under furnace conditions

98/04008 Combustion of a single wood log under furnace conditions

ONE-PARAMETER MODELS FOR UNSATURATED HYDRAULIC CONDUCTIVITY

Simple one-parameter models for predicting changes in unsaturated soil hydraulic properties with changing soil-water content are useful, considering the great uncertainty and variability in the hydraulic parameters, and the models are often used for stochastic simulations of water and solute transport under field conditions. Two general one-parameter models for predicting relative hydraulic conductivity between water saturation and −350 cm H2O of soil-water potential are presented. The two new hydraulic conductivity models were labeled the Double Log Conductivity (DLC) and the Single Log Conductivity (SLC) models and represent modifications of the Campbell and the Libardi et al. conductivity models, respectively. The DLC and SLC model constants were optimized based on conductivity and retention data from a broad texture group of 40 sieved soils, but they can be calibrated easily to specific series of soils. The main parameter in both models (the Campbell soil-water retention parameter, b) can be estimated readily from soil texture or water retention data. Both models gave improved predictions of relative hydraulic conductivity in sieved soils compared with traditionally used one-parameter models. DLC and SLC model predictions were further compared with conductivity data from 10 undisturbed soils. The results suggested that the new models are also useful for predicting both relative and absolute hydraulic conductivity in undisturbed soil, but in this case, a calibration of the model constants based on a larger undisturbed soil data set is recommended.

Grain growth kinetics of Li 3PO 4-doped calcium carbonate

Grain growth mechanisms of calcium carbonate doped with lithium phosphate were determined. With small lithium phosphate addition, an abnormal needle-like grain growth was observed. Addition of the dopant as solid solution in calcite follows the equation: Li 3PO 4 CaCO 3 →3(Li i +) + + V Ca 2+ 2− + (PO 4 3−) CO 3 2+ −. In slightly higher quantities (2 wt.%) above the solubility limit of Li 3PO 4, a second phase segregated at the grain boundaries. Whatever the thermal treatment (temperature, CO 2 partial pressure), the grain distribution was self-similar ( G( t)/ G ( t))=time independent) and followed a single log normal law. The grain growth kinetics can be described by the equation: d G /d t= k( G −1- G c −1). The grain growth was controlled by the mobility of the second phase.

Simulated grading of logs with an x‐ray log scanner‐grading accuracy compared with manual grading

Today sawmills have started to use automatic methods for log grading. The methods used are either optical or gamma‐ray scanners. However, the signals from these scanners are too coarse for accurate log grading and for good control of the sawing process at the single log level. The objective of the present study was to determine the grading accuracy of a log‐scanner with two industrial X‐ray sources. The grading accuracy was compared with the accuracy of manual grading. The results showed that the manual grading of logs and boards is difficult. The accuracy of manual grading was low and the automatic grading systems were more reliable than manual ones. Possibilities for improving the automatic grading systems are discussed.

Multi-Well Subsurface Study of the Stratigraphic Sequence of the Potter Formation in the Midway-Sunset Field, Kern County, California: ABSTRACT

To understand the stratigraphic nature of the Potter Formation reservoirs, a multi-well study along a west-east cross-section was done using dipmeter, Formation MicroScanner, and FMI[trademark] (Fullbore Formation Microlmager) data. Thermal EOR wells are drilled only into the heavy oil-bearing portion of the reservoir, thus each well does not penetrate the complete Potter sequence, but penetrates successively younger sandstone and conglomerate members from west to east. Wireline logs and continuous core data were used for correlation and calibration of the dip and image data. The image data revealed detailed stratification, bedding, and sedimentary structures, identifying conglomeratic, bioturbated and stratified sequences. Correlation with continuous core clarified which features were more interpretive. The image data, available on three of the eleven wells, was then correlated to dipmeter data, both in the form of computed dip data and interpolated electrical images. Each of the eleven wells penetrated only one or two members of the Potter Formation. Using the dip data, it was possible to reconstruct a true stratigraphic thickness type log of the Potter Formation. The interpreted stratigraphic data, revealing bedded, bioturbated, and conglomeratic depositional systems was combined into a single type log of the Potter Formation. The resultant type log can be usedmore » for various sequence stratigraphic, engineering, and thermal EOR reservoir characterization applications in the Midway-Sunset Field.« less

Fluvial Architecture of Selected Middle Pennsylvanian Sandstones, Port of Catoosa, Rogers County, Oklahoma: ABSTRACT

Abstract The facies architecture of fluvial-dominated delta plain systems were reconstructed for several Middle Pennsylvanian sandstones. The study area incorporates approximate 640 acres centered on the Amoco experimental drilling site near Port of Catoosa. Data included conventional logs from 11 wells, and core plus microresistivity images from a single well. Architecture elements recognized are divided in four hierarchical levels, in order of decreasing rock volume: multistacked discrete genetic interval; individual discrete genetic interval (DGI); facies; and stratification pattern of a single facies. Conventional logs are used to correlate and map multistacked DGI, individual DGI, and facies. Core and microresistivity images are used to resolve facies and stratification patterns in the vicinity of the experimental well. Using azimuthal relationships among architecture elements, the location of the experimental well within the depositional systems are determined. Examples of architectural reconstruction include the following. The Bartlesville sandstone consists of splay facies in the upper part and channel-fill facies on the lower part as two individual discrete genetic intervals. The channel-fill facies shows a fining-upward profile with cross strata at the bottom to parallel strata and ripple laminae at the top. The splay facies is made up of small-scale cross strata, climbing ripple laminae, and parallel strata. Lower Skinner sandstone is 50 feet thick and in conventional well logs forms a single bell-shaped log profile. However, the microresistivity log clearly shows that it is composed of two DGI's, each represented by channel-fill facies.

ARIES/CSA

This paper presents an algorithm, called ARIES/CSA ( Algorithm for Recovery and Isolation Exploiting Semantics for Client-Server Architectures ), for performing recovery correctly in client-server (CS) architectures. In CS, the server manages the disk version of the database. The clients, after obtaining database pages from the server, cache them in their buffer pools. Clients perform their updates on the cached pages and produce log records. The log records are buffered locally in virtual storage and later sent to the single log at the server. ARIES/CSA supports a write-ahead logging (WAL), fine-granularity (e.g., record) locking, partial rollbacks and flexible buffer management policies like steal and no-force . It does not require that the clocks on the clients and the server be synchronized. Checkpointing by the server and the clients allows for flexible and easier recovery.

Spatial distribution among mycelial individuals of Lycoperdon pyriforme occurring on decaying logs

Multiple basidiomes of Lycoperdon pyriforme are often produced on decaying logs. Data from vegetative incompatibility interactions and isozyme analysis were used to identify and determine the boundaries of mycelial individuals as reflected by the distribution of basidiomes. Tissue cultures from randomly selected basidiomes from eleven different logs found at one of three different sites in Kansas and Missouri revealed that, in most cases, isolates collected from a single log belonged to the same vegetative compatibility group and isozyme phenotype. Thus it appears that all basidiomes on a log are usually the products of a single individual growing throughout the log. Several possibilities exist which might explain these observations. This fungus in nature may be sporadic and of low abundance; a natural consequence of the scattered distribution of logs and fallen wood upon which it grows and fruits. Hence, it may be a relatively rare event for any given log to become successfully occupied by one individual, let alone many. Another possibility is that vegetative incompatibility among unlike genotypes causes the consequent exclusion of new individuals from an already established site. Adjacent logs were occasionally colonized by the same genotypes suggesting that some individuals may be able to move from log to log. However, since most logs were occupied by genetically unique individuals, long-distance transport and/or sexual reproduction is probably an important factor in spatial distribution.

MLR: a recovery method for multi-level systems

To achieve high concurrency in a database system has meant building a system that copes well with important special cases. Recent work on multi-level systems suggest a systematic path to high concurrency. A multi-level system using locks permits restrictive low level locks of a subtransaction to be replaced with less restrictive high level locks when sub-transactions commit, enhancing concurrency. This is possible because sub-transactions can be undone via high level compensation actions rather than by restoring a prior lower level state. We describe a recovery scheme, called Multi-Level Recovery (MLR) that logs this high level undo operation with the commit record for the subtransaction that it compensates, posting log records to only a single log. A variant of the method copes with nested transactions, and both nested and multi-level transactions can be treated in a unified fashion.

The number and distribution of incompatibility factors in natural populations of Pleurotus ostreatus and Pleurotus sapidus

Pairings of single-spore isolates from different basidiocarps were made to examine the numbers and distributions of incompatibility factors in the tetrapolar basidiomycetes Pleurotus ostreatus and Pleurotus sapidus. These factors do not appear to be randomly distributed, with multiple basidiocarps on a single tree or log arising from a single mycelium, multiple basidiocarps on a single tree or log sharing a single common monokaryotic parent, and a tendency toward spatial clustering of factors even when multiple basidiocarps from the same tree or log are excluded from the analyses. For one 30-km2 collection area, the estimated numbers of A and B factors in the P. ostreatus population were 126 and 354, respectively, yielding an estimated outbreeding efficiency of 0.99. Estimated outbreeding efficiencies were quite high [Formula: see text] even in a sample taken from a very small area (0.09 m2), illustrating the ability of the tetrapolar mating system to simultaneously prevent self mating and minimize the number of incompatible matings. Key words: Basidiomycotina, fungi, mating system, population genetics.

Small sample estimation of log odds ratios from logistic regression and fourfold tables

Schaefer has proposed a method to correct the maximum likelihood logistic regression coefficients for bias in small samples. We show here that this reduces, in the special case of a single dichotomous regression variable, to an earlier result of Haldane, for the estimation of a single log odds ratio. This paper reviews various estimators for the log odds ratio in a fourfold table, and compares the properties of two by complete enumeration in sets of tables with small sample sizes. The first of these, also due to Haldane, is based on the addition of 1/2 to each cell of the table; the second is where 1/2 is added to all cells of the table only if a zero frequency arises. We evaluate the bias and mean squared error of both of these estimators in sets of tables with various sample sizes and odds ratios. Haldane's estimator usually has lower bias and MSE, and so we do not in general recommend the practice of adding 1/2 only as necessary. Exceptions might occur if one has good a priori estimates of the outcome probabilities in the two samples under comparison.