Log Correlation Research Articles

Antibody-catalyzed benzoin oxidation as a mechanistic probe for nucleophilic catalysis by an active site lysine.

Aldolase antibody 24H6, which was obtained by reactive immunization against a 1,3-diketone hapten, is shown to catalyze additional reactions, including H/D exchange and oxidation reactions. Comparison of the H/D exchange reaction at the alpha-position of a wide range of aldehydes and ketones by 24H6 and by other aldolase antibodies, such as 38C2, pointed at the significantly larger size of the 24H6 active site. This property allowed for the catalysis of the oxidation of substituted benzoins to benzils by potassium ferricyanide. This reaction was used as a mechanistic probe to learn about the initial steps of the 24H6-catalyzed aldol condensation reaction. The Hammett correlation (rho=4.7) of log(k(cat)) versus the substituent constant, sigma, revealed that the reaction involves rapid formation of a Schiff base intermediate from the ketone and an active site lysine residue. The rate-limiting step in this oxidation reaction is the conversion of the Schiff base to an enamine intermediate. In addition, linear correlation (rho=3.13) was found between log(K(M)) and sigma, indicating that electronic rather than steric factors are dominant in the antibody-substrate binding phenomenon and confirming that the reversible formation of a Schiff base intermediate comprises part of the substrate-binding mechanism.

Detection of formation boundaries and permeable fractures based on frequency-domain Stoneley wave logs

This paper describes a method of detecting formation boundaries, and permeable fractures, from frequency-domain Stoneley wave logs. Field data sets were collected between the depths of 330 and 360 m in well EE-4 in the Higashi-Hachimantai geothermal field, using a monopole acoustic logging tool with a source central frequency of 15 kHz. Stoneley wave amplitude spectra were calculated by performing a fast Fourier transform on the waveforms, and the spectra were then collected into a frequency-depth distribution of Stoneley wave amplitudes. The frequency-domain Stoneley wave log shows four main characteristic peaks at frequencies 6.5, 8.8, 12, and 13.3 kHz. The magnitudes of the Stoneley wave at these four frequencies are affected by formation properties. The Stoneley wave at higher frequencies (12 and 13.3 kHz) has higher amplitudes in hard formations than in soft formations, while the wave at lower frequencies (6.5 and 8.8 kHz) has higher amplitudes in soft formations than in hard formations. The correlation of the frequency-domain Stoneley wave log with the logs of lithology, degree of welding, and P-wave velocity is excellent, with all of them showing similar discontinuities at the depths of formation boundaries. It is obvious from these facts that the frequency-domain Stoneley wave log provides useful clues for detecting formation boundaries.The frequency-domain Stoneley wave logs are also applicable to the detection of a single permeable fracture. The procedure uses the Stoneley wave spectral amplitude logs at the four frequencies, and weighting functions. The optimally weighted sum of the four Stoneley wave spectral amplitudes becomes almost constant at all depths, except at the depth of a permeable fracture. The assumptions that underlie this procedure are that the energy of the Stoneley wave is conserved in continuous media, but that attenuation of the Stoneley wave may occur at a permeable fracture. This attenuation may take place at any one of the four characteristic Stoneley wave frequencies. We think our multispectral approach is the only reliable method for the detection of permeable fractures.

Hydrogen Bonding Contribution to Lipophilicity Parameters. Hydrogen Acceptor and Hydrogen Acceptor Donor Parameters

In our analysis of the composition of lipophilicity parameters by the intermolecular force (IMF) model we have made use of nH, the number of OH and/or NH bonds, as a measure of the hydrogen donor capacity of a substituent; and nn, the number of lone pairs on O and/or N atoms in the substituent, as a measure of the hydrogen acceptor capacity of the substituent. The basis of this method is the reasonable assumption that in 55.6 molar water hydrogen bonding is maximized. The method does not account however for differences in the energy of different types of hydrogen bonds, but further assumes that these differences are to a first approximation negligible. In order to improve the model we have defined a scale of group hydrogen bonding acceptor parameters, ηXHA, and overall hydrogen bond parameters ηXHAD from the water/1-octanol partition coefficients of AkX where Ak is alkyl. These parameters should account for both the extent of hydrogen bonding in water and for the difference in hydrogen bond energies of the various types of hydrogen bonds encountered. Correlations of log P values for Ph(CH2)nX, X1(CH2)X2, and substituted amino acids Xaa with the IMF equation using the ηXHA and ηXHAD parameters demonstrated their use. Correlation of log P values for PhX suggested that for many groups separate sets of ηXHA and ηXHAD values are required when they are bonded to sp2 hybridized carbon rather than sp3 hybridized carbon.

Relationship of Somatic Cell Count, Physical, Chemical and Enzymatic Properties to the Bacterial Standard Plate Count in Different Breeds of Dairy Goats

The objective of the present study was to investigate the accuracy of mastitis diagnostic indicators for different dairy goat breeds. Biweekly milk samples were collected from individual half mammary gland of seven Saanenand seven Alpine dairy goats in the period of 40 to 120 days in milk. With threshold value set at 2.8 and 3.1 for Alpine and Saanen dairy goats, respectively, log (SPC) offered good sensitivity (0.89, 0.93), specificity (0.88, 0.95), positive predictive value (0.75, 0.85) and negative predictive value (0.95, 0.98) as a mastitis diagnostic tool. The correlations of log (SPC) with milk yield, log (SCC), ALP, LDH, Na + , K + and EC were significant in Saanen dairy goats (p<0.05), with the highest correlation coefficient (0.653) existing between log (SPC) and log (SCC). The correlations of log (SPC) with milk yield, milk fat, milk protein, log (SCC), Na + , K + , EC were significant in Alpine dairy goats (p<0.05), with the highest correlation coefficient (0.416) existing between log (SPC) and log (SCC). There were different best-fit regression equations with different multiple diagnostic indicators for Saanen and Alpine dairy goats. In conclusion, different breeds of dairy goats may have to adapt different mastitis diagnostic parameters for a better diagnosis.

Evidence of reservoir compartmentalization by calcite cement layers in deepwater sandstones, Bell Canyon Formation, Delaware Basin, Texas

Abstract Sandstones of the Upper Permian Bell Canyon Formation were deposited by turbidity currents in a basin-floor setting. The sandstones were deposited in a channel-levee system that terminated in broad lobes; overbank splays filled topographically low inter-channel areas. Diagenesis and reservoir quality of the sandstones were examined in cores from East Ford field, which is undergoing a CO 2 flood. Porosity and permeability are controlled by calcite cement, mainly concentrated in layers ranging from 5 to 40 cm in thickness. In a new infill well, initial production was of a high gas volume that contained a high concentration of CO 2 from the interval beneath several low-permeability, calcite-cemented layers. The CO 2 was most likely from an injector well and was trapped below the calcite layers. Geophysical log correlations support the interpretation that some calcite layers are laterally continuous over a distance of at least 300 m, causing vertical compartmentalization in the reservoir.

Kinetic studies of rat kidney gamma-glutamyltranspeptidase deacylation reveal a general base-catalyzed mechanism.

The enzyme gamma-glutamyltranspeptidase (GGT) is critical to cellular detoxification and leukotriene biosynthesis processes, as well as amino acid transport in kidneys. GGT has also been implicated in many important physiological disorders, including Parkinson's disease and inhibition of apoptosis. It binds glutathione as a donor substrate and initially forms a gamma-glutamyl-enzyme complex that can then react with a water molecule or an acceptor substrate (usually an amino acid or a dipeptide) to form glutamate or a product containing a new gamma-glutamyl-isopeptide bond, respectively, thus regenerating the free enzyme. Despite its important role in human physiology, the mechanisms of the reactions catalyzed by GGT are not well-known, particularly with respect to the deacylation step. We have synthesized a series of methionine amide derivatives whose alpha-ammonium groups have different pK(a) values. By using these compounds as acceptor substrates for GGT, we have constructed a Brønsted plot and obtained a good correlation for log(k(norm)(cat,b)/K(b)) versus pK(a)(NH+) with a slope beta(nuc) of 0.84, consistent with a rate-limiting nucleophilic attack of the substrate amine on the acyl-enzyme intermediate. Isotope effect studies have shown that there is a proton in flight at the transition state, consistent with concerted deprotonation of the nucleophilic amine effected by an unidentified general base. A bell-shaped pH-rate profile has also been obtained for the deacylation step, reflecting the pK(a) values of the acceptor substrate (and/or that of a general base residue) and of a putative general acid that may be necessary for reprotonation of the active site nucleophile upon regeneration of the free enzyme. These data allow us to propose for the first time a detailed mechanism for this important step of the GGT-mediated reaction and to speculate about the origin of its acceptor substrate specificity.

The development and seismic expression of synsedimentary features within the Chalk of southern England

Seismic reflection data acquired onshore to the north of Bournemouth, southern England, image clearly a series of prominent concave-up (troughs or depressions) and concave-down (mounded) structures within the White Chalk Subgroup. The Chalk lithostratigraphy in the area of study is established from borehole geophysical log correlations. These correlations then provide calibration of the seismic reflection data, indicating that the structures are concentrated at levels between the Lewes Nodular Chalk Formation and Tarrant Chalk Member, and towards the base of the Portsdown Chalk Formation. Onlap, downlap and truncation of reflectors are observed, with the most dramatic features forming a stacked series directly overlying faulting of Jurassic strata. Similar stratal geometries have been described from comparable levels in the Chalk of the North Sea, and in outcrop in Britain and France. To many they represent channels formed by submarine erosion and redeposition of the Chalk during relative sea-level falls, linked to tectonics. We also interpret a number of apparently incisive structures and slumped infill sequences described here as being of primary syndepositional origin. The slumping and the close association of these features with underlying faults, and proximity to nearby major crustal faults, may be indicative of submarine erosion of the Chalk caused by sea-level changes linked to syndepositional fault movements. However, evidence of toplap–downlap pairs is also suggestive of more aggradational mounding or laterally migrating surfaces or facies belts. The presence of any such structures implies rapid lateral variations in the Chalk that would have implications not only for aquifer management and future storage schemes but also during the processing of seismic reflection data and general studies and correlations of the Chalk across southern Britain.

Adduct formation of methyltrioxorhenium with mono- and bidentate nitrogen donors: formation constants.

The coordination of N-donor ligands to MTO (methyltrioxorhenium) is governed by both electronic and steric effects. For example, the binding constant of pyridine to MTO is 196.6 L mol(-)(1), whereas that of the better donor 4-picoline is 732 L mol(-)(1) and that of the sterically encumbered 2,6-di-tert-butyl-4-methylpyridine is <1 L mol(-)(1). Equilibrium constants have been evaluated for this reaction, MTO + L = MTO.L, where L comprises mono- and bidentate N-donor ligands. The values of log K for monodentate ligands range from <0 for 2-substituted pyridines to 3.3 for 1-butylimidazole and for bidentate ligands from 2.2 for 2,2'-bipyridine to 5.27 for 4,7-dimethyl-1,10-phenanthroline at 25 degrees C in chloroform. A successful correlation of log K with pK(a) of L was realized except in the case of 2-substituted ligands, where steric effects make K smaller than expected from the proton basicity of L.

Removal of exganic sulfur from coal by perchloroethylene extraction and ultrasonic wave : Yu, H.-M. et al. Zhongguo Kuangye Daxue Xuebao, 2002, 31, (3), 289–292. (In Chinese)

Mineral resources estimation comprises basically two stages: (i) data collection, analysis and validation, and (ii) the estimate of the grades and tonnes of the deposit. The most often applied method for obtaining geological data during mineral exploration is rotary drilling with total core recovery. High drilling costs make borehole geophysical logging attractive to obtain the maximum possible information from each borehole helping to understand ore intersections, grades variability, and extension of the deposit and its continuity. In this paper, borehole geophysical logging was used to enhance the sampling survey and to derive grades indirectly (without lab analysis) with a certain amount of uncertainty. Soft indicator kriging (IK) was selected to estimate coal quality by combining hard data from drill holes and soft data from geophysical logging correlation. The method showed to be adequate to incorporate the uncertainty associated with the geophysical derived grade values. The results were compared to the conventional procedures using grades determined via core analysis and ordinary kriging. Borehole geophysical logging proved to be essential to define the features of ore deposit and soft IK provided results with acceptable precision and accuracy if compared to the model provided by ordinary kriging and hard data.

Pharmaceutical profiling method for lipophilicity and integrity using liquid chromatography–mass spectrometry

A method is described for the simultaneous profiling of sample lipophilicity, integrity, and purity. The method is rapid and is applicable to high throughput profiling of pharmaceutical properties in drug discovery. A short Polaris C 18 column is used with a rapid, wide-polarity mobile phase gradient, UV detection, and MS analysis. The lipophilicity of each component is estimated from a calibration curve using six drug or organic compounds and plotting their respective measured retention time versus Log D 7.4 (literature). The correlation of Log D 7.4 (literature) to Log D 7.4 (HPLC) for 60 structurally diverse drugs has a correlation coefficient r 2 of 0.89. The method is applicable to compounds with MW>200 and retention time>1.5 min for rapid, initial pharmaceutical profiling in drug discovery.

Biomarker responses and PAH uptake in Mya truncata following exposure to oil-contaminated sediment in an Arctic fjord (Svalbard)

Expanding industrial activity (notably oil and gas exploration) in the Arctic requires assessment of the potential impact of chemicals on marine organisms living in seawater at low temperature. The bivalve Mya truncata is common in Svalbard fjord (Norway) where it experiences low temperature throughout the year. To measure the impact of polycyclic aromatic hydrocarbons (PAH) on M. truncata, the responses of three biomarkers [total oxyradical scavenging capacity-assay (TOSC), plasma membrane stability of haemocytes and respiration rates] were investigated from bivalves exposed to sediment contaminated with a PAH mixture (crude oil). After two weeks of exposure to the contaminated sediment, TOSC showed no change. The high TOSC value (4010±1339 unit mg −1 protein) of Mya truncata (control group) is thought to protect biomolecules with a low turnover rate efficiently in a low food availability environment. In the exposed bivalves, the haemocyte cellular membranes were significantly destabilised compared with controls ( P<0.05). Respiration rate of control and PAH-exposed individuals (0.055±0.020 mg O 2 dw −1 h −1) was similar and relatively low as is typical for polar bivalves, reflecting a strategy to minimise energy expenditure to cope with 9 months of starvation. Bioaccumulation of PAH by M. truncata was also low, due probably to a combination of low metabolic rate and reduced solubility of the oil compounds at low temperature. Data indicated an uptake of mainly low molecular weight compounds (two and three ring molecules). A good correlation of logBAF lipid (bioaccumulation factor) and log K ow (octanol/water partitioning coefficient) was shown ( r 2=0.87). Tissue sensitivity and/or functional differences (digestive gland vs. haemocytes), PAH uptake route (dietary vs. gills), the low metabolic rate of M. truncata and the low environmental temperature (reducing the bioavailability of PAH) are factors that help explain these findings.

Multiparametric probing of intermolecular interactions with fluorescent dye exhibiting excited state intramolecular proton transfer

Excited-state intramolecular proton transfer (ESIPT) in 3-hydroxyflavone dyes allows us to record, in addition to common spectroscopic parameters, the positions of absorption (νabs) and emission (νN*) maxima, two new parameters: the position of the emission maximum of the ESIPT product T* state (νT*) and the intensity ratio of the two emission bands (IN*/IT*). An attempt was made to find a correlation between these parameters and physicochemical characteristics of microenvironment: polarity f(e), electronic polarizability f(n) and H-bond donor ability. A detailed spectroscopic study of 4′-diethylamino-3-hydroxyflavone in a set of 21 representative solvents demonstrates that the Stokes shift of the N* band (νabs − νN*) correlates strongly with the Lippert function L = f(e) − f(n), and this correlation does not depend on the effects of intermolecular H-bonding, while the correlation of log(IN*/IT*) with polarity f(e) can be represented by linear functions that are different for protic and aprotic environments. Cross-correlation analysis of the spectroscopic parameters provides criteria to distinguish specific (H-bonding and other) from universal probe interactions with the environment. We suggest an algorithm, which uses four spectroscopic parameters νabs, νN*, νT* and log(IN*/IT*) to provide a simultaneous estimation of three microenvironment characteristics: f(e), f(n) and H-bond donor ability. An application of this algorithm in the studies of binary solvent mixtures, reverse micelles and binding sites of proteins demonstrates the power of this approach and suggests a unique possibility to develop a new generation of fluorescence probes and labels in the 3-hydroxyflavone family for studying complex microheterogeneous systems in physical chemistry, colloid chemistry and the biological sciences.

From seismic data to core data: an integrated approach to enhance reservoir characterization

Abstract Integrated structural analyses of seismic and various well data are necessary to optimize hydrocarbon reservoir characterization. However, there are many published examples from the oil and gas industry where single data types are analysed but not integrated. This may lead to erroneous interpretations and drainage strategies. As illustrated by an example from the area around well 34/10-B-12 in the North Sea Gullfaks Field, integrated structural interpretation should typically utilize all available seismic surveys, well log correlation data, dipmeter data and core data. Interpretation of seismic data helps in the understanding of large-scale structural and stratigraphic geometries. Time-lapse (4D) seismic helps to identify changes in reservoir properties caused by injection and production. Well log correlation data are used to document variations in zonation thickness caused by sedimentological or structural changes. Dipmeter data tie observations of bedding orientation from seismic data to subseismic scale. Core data represent the most detailed (millimetre to metre scale) data available and can yield information on rock properties as well as sedimentological and (micro)structural features. Small-scale deformation structures such as deformation bands and fractures can typically be identified and characterized. In addition, it is possible from unorientated cores to find the orientation of bedding and deformation structures. This information is compared to observations from dipmeter data, well log correlation data and seismic data to improve the interpretation. Well 34/10-B-12 is a hanging wall injector near one of the large-scale faults in the Gullfaks Field. Several 3D seismic surveys are available from the area, as are standard well log data, dipmeter information and cores. Together, the data range from millimetre to kilometre with some overlap between the data types. Through integrated analysis, pitfalls such as interpreting any linear feature on timedip attribute maps as faults has been avoided. Also, a geometric relation between core-scale and seismic-scale faults has been established, and it has been possible to relate small-scale and large-scale structures in a model which is consistent with all the available data.

Porosity images from well logs

Porosity images are graphical representations of the lateral distribution of rock porosity estimated from well log data. We present a methodology to produce this geological image entirely independent of interpreter intervention, with an interpretative algorithm approach, which is based on two types of artificial neural networks. The first is based on neural competitive layer and is constructed to perform an automatic interpretation of the classical ρ B– φ N cross-plot, which produces the log zonation and porosity estimation. The second is a feed-forward neural network with radial basis function designed to perform a spatial data integration, which can be divided in two steps. The first refers to well log correlation and the second produces the estimation of lateral porosity distribution. This methodology should aid the interpreter in defining the reservoir geological model, and, perhaps more importantly, it should help him to efficiently develop strategies for oil or gas field development. The results or porosity images are very similar to conventional geological cross-sections, especially in a depositional setting dominates by clastics, where a color map scaled in porosity units illustrates the porosity distribution and the geometric disposition of geological layers along the section.

Statistical differentiation of bananas according to their mineral composition.

The concentrations of Na, K, Ca, Mg, Fe, Cu, Zn, and Mn were determined in banana cultivars Gran enana and Pequeña enana cultivated in Tenerife and in cv. Gran enana bananas from Ecuador. The mineral concentrations in the bananas from Tenerife and from Ecuador were clearly different. The cultivar did not influence the mineral concentrations except in the case of Fe. Variations according to cultivation method (greenhouse and outdoors) and farming style (conventional and organic) in the mineral concentrations in the bananas from Tenerife were observed. The mineral concentrations in the internal part of the banana were higher than those in the middle and external parts. Representation of double log correlations K-Mg and Zn-Mn tended to separate the banana samples according to origin. Applying factor and cluster analysis, the bananas from Ecuador were well separated from the bananas produced in Tenerife, and therefore, these are useful tools for differentiating the origin of bananas.

Serum insulin level, disease stage, prostate specific antigen (PSA) and Gleason score in prostate cancer.

In the present study, we assessed the relationship of serum insulin levels and three surrogate markers of recurrence, T stage, PSA, and Gleason score, in men with localized prostate cancer. Participants in our study were found through urology and radiation oncology clinics, and all eligible patients were asked to take part. All patients were asymptomatic and had been initially diagnosed on the basis of rising PSA or abnormal physical examination. Histological confirmation of diagnosis was obtained for all subjects. Serum insulin levels were determined by chemoluminescent assay with a standard, commercially available instrument. Patients were divided into three previously defined risk groups: Low risk: PSA ⩽10, stage ⩽T2a, or Gleason grade ⩽6. Medium risk: 10 <PSA ⩽15, Gleason 7 or stage T2b. High risk: Gleason >7, tumour in seminal vesicle biopsy, PSA >15 or stage T2c or T3. One hundred and sixty-three men with prostate cancer were studied. There was a significant increase in serum insulin with risk group (P=0.003, one way anova). Tukey's multiple range test showed that the insulin levels of high risk patients were significantly higher than the insulin levels of medium and low risk patients (P=0.05) but the insulin levels of medium and low risk patients were not significantly different from one another. Multivariate linear regression, with insulin as the dependent variable, Gleason score, PSA, and T stage (T1, T2, T3) as the independent variables, was significant overall (P<0.001, r2=0.120). Increased T stage was independently correlated with increased serum insulin levels (P<0.001). Gleason score was negatively, insignificantly correlated with serum insulin level (P=0.059). The positive correlation of PSA and insulin level was not significant (P=0.097). To assure normal distribution of insulin and PSA values, the regression was repeated with log (insulin) as the dependent variable, log (PSA), T stage (T1, T2, T3), and Gleason score as independent variables. The regression was significant overall (P=0.002, r2 =0.095). Increased T stage was independently correlated with increased log (insulin level) (P=0.026). Gleason score was negatively, insignificantly correlated with log (insulin) level (P=0.728). The positive correlation of log (PSA) and log (insulin) levels was significant (P=0.010). The relationship between increased insulin level and advanced tumour stage in prostate cancer we describe here is biologically quite plausible, since insulin is a growth factor. Further studies may document whether serum insulin levels might be a useful biomarker of prostate cancer stage.British Journal of Cancer (2002) 87, 726–728. doi:10.1038/sj.bjc.6600526 www.bjcancer.com© 2002 Cancer Research UK

Temperature and organic matter dependence of the distribution of organochlorine compounds in mountain soils from the subtropical Atlantic (Teide, Tenerife Island).

Surface soil samples from Teide mountain (Canary Islands) have been analyzed for polychlorobiphenyls (PCBs), DDTs, hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), and pentachlorobenzene. The samples were situated between 10 and 3400 m above sea level being distributed below, at, and above the permanent inversion layer system characteristic of the subtropical Atlantic. All OC concentrations were, in general, low when compared with the data from urban, agricultural, or woodland soils reported elsewhere. Typical ranges were 0.04-9.2, 0.01-40, 0.001-1, or 0.01-3.2 ng x g(-1) dry weight for total PCBs, DDTs, HCHs, or HCB, respectively. These compounds exhibited a high dependence from the soil total organic carbon (TOC), showing high coefficients in the log(OC) versus log(TOC) correlations. The slopes of the curve fitted straight lines were, in turn, highly correlated to the log-transformed octanol-air coefficients of the compounds. This overall OC distribution points to steady-state conditions for the concentrations of these compounds in these mountain soils, in equilibrium with TOC. The equilibrium conditions are reached, despite the restrictions to convective air movement associated to the permanent atmospheric inversion layer at these latitudes. In addition, the log-transformed TOC-normalized concentrations of most PCBs, HCB, and pentachlorobenzene exhibit a good correlation with the reciprocal of average annual atmospheric temperatures also showing a temperature dependence for their distribution in the high mountain system. The calculated pseudo-enthalpies for this dependence, 120-160 kJ x mol(-1), exhibit higher values than those of octanol-air phase change calculated from laboratory experiments in previous studies, 66-93 kJ x mol(-1). The difference suggests a higher affinity of OC to soils than that corresponding to simple adsorption mechanisms.

Transport across 1,9-decadiene precisely mimics the chemical selectivity of the barrier domain in egg lecithin bilayers

The barrier domain solubility-diffusion theory of lipid bilayer permeability relates the permeability coefficient (Pm) to the solute's partition coefficient (PCbarrier/w) and diffusion coefficient (Dbarrier) in the ordered chain region of the bilayer that serves as the barrier region for polar permeants. To select the best solvent to mimic the barrier domain, permeability coefficients across a layer of 1,9-decadiene were compared with permeability coefficients from bilayer transport. Rate constants for transport, k, of α-methyl substituted analogues of p-toluic and p-methylhippuric acid were measured across a layer of 1,9-decadiene embedded in a PTFE filter membrane placed between two aqueous solutions in side-by-side diffusion cells. Permeability coefficients (P1,9-decadiene) were normalized to that obtained for p-toluic acid, which was included in donor solutions. The correlation of log(Pbilayer) versus log(P1,9-decadiene) was linear with a slope of 0.99 ± 0.02 SD, indicating that 1,9-decadiene precisely mimics the egg lecithin bilayer barrier domain in its chemical selectivity. Using the decadiene membrane transport method to indirectly estimate partition coefficients for similarly sized permeants extended the range of measurable values beyond those readily attainable by the traditional shake-flask method, allowing measurement of 1,9-decadiene/water PCs as low as 3 × 10−7. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:640–646, 2002

IR properties of H2O megamaser galaxies, pumping mechanisms, and central sources

The IR-properties of all the host galaxies which exhibit H2O megamaser emission have been studied in this paper. The most striking feature is the anticorrelation of the log[S(60)/S(100)] vs. log[S(12)/S(25)] and log[S(25)/S(60)] vs. log[S(12)/S(25)], and the correlation of log[S(60)/S(100)] vs. log[S(25)/S(60)]. These anticorrelations and the correlation in the flux density ratios can be explained by the coexistence of large and very small dust particles. The relationship between the luminosity of the H2O megamaser and the infrared luminosity vs. the flux density ratio of S(60)/S(100), S(25)/S(60), and S(12)/S(25) have been studied. The correlation of the luminosity vs. S(60)/S(100) and the luminosity vs. S(25)/S(60), and the anticorrelation of the lumonosity vs. S(12)/S(25) are obtained, respectively. The pumping mechanism of the H2O megamaser is discussed according to the these results. The characteristics of the central sources are also studied, according to these relationships.

The Ursa Major Cluster of Galaxies. V. HiRotation Curve Shapes and the Tully‐Fisher Relations

The Tully-Fisher relations for a complete sample of spirals in the Ursa Major cluster is investigated. The merits of combining B, R, I and K' photometry with HI rotation curves (RCs) have been exploited. In addition to the corrected HI global profile widths W_{R,I}^i, the HI RCs allow direct measurements of the maximum rotation Vmax and the amplitudes Vflat of the outer flat parts. The dynamical state of the gas disks could also be determined in detail. For large galaxy samples, the M^{b,i}_R - Log(W_{R,I}^i) correlation in conjunction with strict selection criteria is preferred for distance determinations with a 7% accuracy. Galaxies with rising RCs at the last measured point lie systematically on the low velocity side of the TF-relation. Galaxies with partly declining RCs (Vmax>Vflat) tend to lie on the high velocity side when using W_{R,I}^i or Vmax. These trends are eliminated when Vflat is used. The M^{b,i}_B - Log(2Vflat) residuals correlate consistently with morphology, color, surface brightness and gas mass fraction. These correlations are absent for the near-IR M^{b,i}_K' - Log(2Vflat) residuals. The tightest correlation (Xred=1.1) is found for the M^{b,i}_K' - Log(2Vflat) relation with a slope of -11.3 +/- 0.5 and a total scatter of 0.26^m with a most likely intrinsic scatter of zero. The tightness of the near-IR correlation is preserved when converting it into a baryonic TF-relation which has a slope of -10.0 for (Mgas/L_K')=1.6 while a zero intrinsic scatter remains most likely. The tightness of the near-IR and baryonic correlations suggests that the TF-relation reflects a correlation between the dark matter halo mass, indicated by Vflat, and the total baryonic mass Mbar where Mbar~Vflat^4. The distribution of the baryons inside halos of similar mass is irrelevant for this relation.