Quantification of Chemotaxis to Naphthalene by Pseudomonas putida G7

ABSTRACT The capillary assay was used to quantify the chemotactic response of Pseudomonas putida G7 to naphthalene. Experiments were conducted in which the cell concentration in the assay chamber, the naphthalene concentration in the capillary, or the incubation time was varied. Data from these experiments were evaluated with a model that accounted for the effect of diffusion on the distribution of substrate and the transport of cells from the chamber through the capillary orifice. By fitting a numerical solution of this model to the data, it was possible to determine the chemotactic sensitivity coefficient, χ0. The mean of the best-fit values for χ0from the three types of experiments was 7.2 × 10−5cm2/s. A less computationally intensive model based on earlier approaches that ignore cell transport in the chamber resulted in χ0 values that were approximately three times higher. The models evaluated in the present study could simulate the results of capillary assays only at low chamber cell concentrations, for which the effect of consumption on the distribution of substrate was negligible. Results from this work suggest that it is possible to use the capillary assay to quantify taxis towards environmentally relevant chemoeffectors that have low aqueous solubility.

Download Full-text

Helium, [Fe/H] Abundances and the HR (Log TEFF, MBol) Diagram With Hipparcos Data of The Four Nearest Open Clusters: Hyades, Coma Berenices, The Pleiades and Praesepe

Highlights of Astronomy ◽

10.1017/s1539299600022206 ◽

1998 ◽

Vol 11 (1) ◽

pp. 565-565

Author(s):

G. Cayrel de Strobel ◽

R. Cayrel ◽

Y. Lebreton

Keyword(s):

Main Sequence ◽

Open Clusters ◽

Main Sequence Stars ◽

Spectroscopic Analyses ◽

Solar Metallicity ◽

Metal Abundances ◽

The Mean ◽

The Moment ◽

The One ◽

Best Fit

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.

Download Full-text

PMTools – a new program for paleomagnetic data analysis and visualization

10.5194/egusphere-egu21-3474 ◽

2021 ◽

Author(s):

Ivan Efremov ◽

Roman Veselovskiy

Keyword(s):

Data Analysis ◽

Paleomagnetic Data ◽

Use Case ◽

Quality Performance ◽

Analysis Process ◽

Data Formats ◽

Cross Platform ◽

The Mean ◽

Near Future ◽

Best Fit

There are many programs for the analysis and visualization of paleomagnetic data, but each of them is good only in a certain use case and does not allow to perform a full cycle of paleomagnetic operations. Therefore, one has to resort to using a number of programs to complete the full path of processing paleomagnetic data. You often have to convert data from one format to another, manually vectorize charts, and generally spend more time and effort than could theoretically be spent. Thus, there is a long overdue need for a universal program capable of fast, convenient and high-quality performance of a full cycle of paleomagnetic operations. A set of programs written by Randy Enkin (Enkin, 1996) for DOS was taken as a time-tested example of such a program. The choice fell on them, since these programs (although they are very outdated) allow performing a full cycle of paleomagnetic operations and do it as conveniently and efficiently as possible for that time.Our goal is to create a program devoid of all of the above disadvantages and capable of developing indefinitely as modular opensource software by the efforts of all people interested in this.The result of our work is PMTools &#8211; a cross-platform software for statistical analysis and visualization of paleomagnetic data. PMTools supports all widely used paleomagnetic data formats and allows you to work with them simultaneously. All charts created in PMTools are vector, adapted for direct using in publications and presentations, and can be exported in both vector and raster formats. At the same time, PMTools implements a full cycle of routine paleomagnetic operations: from finding the best-fit directions to calculating the mean paleomagnetic poles. Moreover, all operations can be performed both with a mouse through a graphical user interface and with hotkeys, which significantly speeds up the data analysis process.&#160;In the near future, PMTools will become a modular open source application, so that each user will be able to add its own modules, thereby expanding the program's functionality.ReferencesEnkin, R.J., 1996. A Computer Program Package for Analysis and Presentation of Paleomagnetic Data, Pacific Geoscience Center, Geological Survey of Canada, http://www.pgc.nrcan.gc.ca/tectonic/enkin.htm.

Download Full-text

Direct calibration of a totally implantable pulsed Doppler ultrasonic blood flowmeter

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1977.232.5.h537 ◽

1977 ◽

Vol 232 (5) ◽

pp. H537-H544

Author(s):

H. V. Allen ◽

M. F. Anderson ◽

J. D. Meindl

Keyword(s):

Linear Regression ◽

Abdominal Aorta ◽

Regression Line ◽

Volume Flow ◽

Flow Profile ◽

Pulsed Doppler ◽

Velocity Flow ◽

The Mean ◽

Best Fit

A totally implantable pulsed Doppler ultrasonic blood flowmeter has recently been developed to provide information on the velocity-flow profile in a vessel as well as its diameter. Volume flow can be indirectly obtained according to the formula: Q = (phi/4)(diam)2-v. In order to determine the accuracy of this estimate, in vivo direct bleedout measurements were performed on the abdominal aorta of six dogs with an overall accuracy in 77 trials of +2.0 +/- 8.7% (mean +/- 1 SD). The best-fit mean linear regression line was found to be: flowmeter output = 1.013-true flow + 5.1 ml/min. The scatter in the flowmeter's accuracy is thought to be due to small variations in the angle of the transducer. The source of the 2% overestimation in the mean accuracy could not be directly attributed to any one condition; the error is sufficiently small that in many cases it can be neglected.

Download Full-text

Influence of temperature on blood pH of the human adult and newborn

Journal of Applied Physiology ◽

10.1152/jappl.1964.19.5.897 ◽

1964 ◽

Vol 19 (5) ◽

pp. 897-900 ◽

Cited By ~ 31

Author(s):

Karlis Adamsons ◽

Salha S. Daniel ◽

Gillian Gandy ◽

L. Stanley James

Keyword(s):

Cell Concentration ◽

Effect Of Temperature ◽

Red Cell ◽

Acid Base ◽

Blood Ph ◽

Influence Of Temperature On ◽

The Mean ◽

Ph Range ◽

Two Populations

The effect of temperature upon pH of blood from adult and newborn humans was investigated. Although the mean ΔpH/ΔT values for the two populations differed, 0.0144/ °C for adults versus 0.0128 for the newborn, this was not peculiar to the source since the temperature-induced pH changes were identical when comparison was made between samples of similar pH and CO2 content. It was shown that even over the physiologic pH range ΔpH/ΔT is not constant but is a function of pH and CO2. No significant changes in ΔpH/ΔT were observed with oxygenation of hemoglobin. The influence of red cell concentration was detectable only when hematocrit values fell below 20%. A graph and an equation for the determination of ΔpH/ΔT of blood with a given pH and CO2 content is presented. acid base Submitted on December 9, 1963

Download Full-text

Relationship of Somatic Cell Count and Total Sulfhydryls in Milk

Journal of Food Protection ◽

10.4315/0362-028x-49.2.110 ◽

1986 ◽

Vol 49 (2) ◽

pp. 110-111 ◽

Cited By ~ 1

Author(s):

DANIEL R. SAMPLES ◽

SUSAN L. DILL ◽

RONALD L. RICHTER ◽

CHARLES W. DILL

Keyword(s):

Somatic Cell ◽

Cell Count ◽

Somatic Cell Count ◽

Milk Protein ◽

Cell Concentration ◽

Chemical Parameters ◽

Milk Samples ◽

The Mean ◽

Relationship Of ◽

The Relationship

Individual milk samples from 32 cows were analyzed to determine the relationship between somatic cell concentration and total sulfhydryl concentration (cysteine plus reduced cystine). A significant relationship was detected between somatic cell count, which ranged from 1.7 × 104 to 1.0 × 107 cells/ml, and total sulfhydryls per gram of milk protein. The regression equation, total sulfhydryls/g of milk protein = 31.96 + 7.99 (log10 somatic cell count) with r2 = 0.19, was calculated. The mean total sulfhydryl concentration was 73.1 μmol/g of protein. The minimal effect of somatic cell concentration on total sulfhydryl concentration indicates that somatic cell concentration should have little influence on chemical parameters of milk protein determined by sulfhydryl analysis when proper experimental controls are used.

Download Full-text

Modified Arthroscopic Latarjet Procedure: Suture-Button Fixation Achieves Excellent Remodeling at 3-Year Follow-up

The American Journal of Sports Medicine ◽

10.1177/0363546519887959 ◽

2019 ◽

Vol 48 (1) ◽

pp. 39-47 ◽

Cited By ~ 3

Author(s):

Jian Xu ◽

Haifeng Liu ◽

Wei Lu ◽

Zhenhan Deng ◽

Weimin Zhu ◽

...

Keyword(s):

Humeral Head ◽

Case Series ◽

Concentric Circle ◽

Vertical Position ◽

Latarjet Procedure ◽

Level Of Evidence ◽

Suture Button ◽

The Mean ◽

Best Fit

Background: Some studies have advocated the use of suture-button fixation during the Latarjet procedure to reduce complications associated with screw fixation. However, the sample size of these studies is relatively small, and their follow-up period is short. Purpose: To investigate the efficacy of the suture-button Latarjet procedure with at least 3 years of follow-up and remodeling of the coracoid graft. Study Design: Case series; Level of evidence, 4. Methods: A total of 152 patients who underwent the suture-button Latarjet procedure between February 2013 and February 2016 were selected, and 128 patients who met the inclusion criteria were enrolled in this study. Preoperative and postoperative clinical results were assessed. The position and healing condition of the coracoid graft and arthropathy of the glenoid and humeral head were also assessed using radiography and 3-dimensional computed tomography (CT). Results: The mean follow-up time was 40.3 ± 5.8 months. There were 102 patients included in this study. The mean visual analog scale score for pain during motion, the American Shoulder and Elbow Surgeons score, the Rowe score, and the Walch-Duplay score were improved considerably. A total of 100 grafts achieved bone union. The overall absorption rate was 12.6% ± 4.3%. Graft absorption mostly occurred on the edge and outside the “best-fit” circle of the glenoid. A vertical position was achieved in 98 grafts (96% of all cases) immediately postoperatively, with the mean graft midline center at the 4 o’clock position. In the axial view, CT showed that 89 grafts were flush to the glenoid, whereas 2 and 11 grafts were fixed medially and laterally, respectively. In all cases, the bone graft and glenoid tended to extend toward each other to form concentric circles during the remodeling process. During follow-up observations, the height of the 11 grafts that were positioned laterally (ie, above the glenoid level) exhibited a wave-curved change. No arthropathy was observed in any patient. Conclusion: Patient outcomes were satisfactory after the modified arthroscopic suture-button Latarjet technique. Graft absorption mostly occurred on the edge and outside the “best-fit” circle of the glenoid. The graft exhibited the phenomenon of ectatic growing when it fused with the glenoid and finally remodeled to a new concentric circle with the humeral head analogous to the original glenoid. Grafts positioned laterally did not cause arthropathy of the joints within the period of the study.

Download Full-text

Titanium Acetabular Component Deformation under Cyclic Loading

Materials ◽

10.3390/ma13010052 ◽

2019 ◽

Vol 13 (1) ◽

pp. 52

Author(s):

Nicholas A. Beckmann ◽

Rudi G. Bitsch ◽

Theresa Bormann ◽

Steffen Braun ◽

Sebastian Jaeger

Keyword(s):

Repeated Measures ◽

Weight Bearing ◽

Acetabular Defect ◽

Acetabular Cup ◽

Partial Weight Bearing ◽

Significant Difference ◽

The Mean ◽

Partial Weight ◽

Acetabular Components ◽

Best Fit

Acetabular cup deformation may affect liner/cup congruency, clearance and/or osseointegration. It is unclear, whether deformation of the acetabular components occurs during load and to what extent. To evaluate this, revision multi-hole cups were implanted into six cadaver hemipelvises in two scenarios: without acetabular defect (ND); with a large acetabular defect (LD) that was treated with an augment. In the LD scenario, the cup and augment were attached to the bone and each other with screws. Subsequently, the implanted hemipelvises were loaded under a physiologic partial-weight-bearing modality. The deformation of the acetabular components was determined using a best-fit algorithm. The statistical evaluation involved repeated-measures ANOVA. The mean elastic distension of the ND cup was 292.9 µm (SD 12.2 µm); in the LD scenario, 43.7 µm (SD 11.2 µm); the mean maximal augment distension was 79.6 µm (SD 21.6 µm). A significant difference between the maximal distension of the cups in both scenarios was noted (F(1, 10) = 11.404; p = 0.007). No significant difference was noted between the compression of the ND and LD cups, nor between LD cups and LD augments. The LD cup displayed significantly lower elastic distension than the ND cup, most likely due to increased stiffness from the affixed augment and screw fixation.

Download Full-text

The quasispecies regime for the simple genetic algorithm with roulette wheel selection

Advances in Applied Probability ◽

10.1017/apr.2017.26 ◽

2017 ◽

Vol 49 (3) ◽

pp. 903-926 ◽

Cited By ~ 2

Author(s):

Raphaël Cerf

Keyword(s):

Genetic Algorithm ◽

Selection Mechanism ◽

Roulette Wheel Selection ◽

Mutation Probability ◽

Roulette Wheel ◽

Simple Genetic Algorithm ◽

Crossover Probability ◽

Mean Fitness ◽

The Mean ◽

Best Fit

Abstract We introduce a new parameter to discuss the behavior of a genetic algorithm. This parameter is the mean number of exact copies of the best-fit chromosomes from one generation to the next. We believe that the genetic algorithm operates best when this parameter is slightly larger than 1 and we prove two results supporting this belief. We consider the case of the simple genetic algorithm with the roulette wheel selection mechanism. We denote by ℓ the length of the chromosomes, m the population size, pC the crossover probability, and pM the mutation probability. Our results suggest that the mutation and crossover probabilities should be tuned so that, at each generation, the maximal fitness multiplied by (1 - pC)(1 - pM)ℓ is greater than the mean fitness.

Download Full-text

Comparison of Hand-Traced and Computer-Based Cephalometric Superimpositions

The Angle Orthodontist ◽

10.2319/052708-283.1 ◽

2009 ◽

Vol 79 (3) ◽

pp. 428-435 ◽

Cited By ~ 2

Author(s):

S. S. Huja ◽

E. L. Grubaugh ◽

A. M. Rummel ◽

H. W. Fields ◽

F. M. Beck

Keyword(s):

Cranial Base ◽

Digital Method ◽

Maxillary Incisor ◽

Friedman Test ◽

Linear Distance ◽

Widespread Acceptance ◽

Computer Based ◽

Digital Methods ◽

The Mean ◽

Best Fit

Abstract Objective: To determine the ability to produce comparable superimpositions using hand tracing and digital methods (Dolphin v10). In addition, if the two methods were comparable, we wanted to determine if a difference existed between the best-fit cranial base superimposition and S-N superimpositions using the digital method. Methods and Materials: Sixty-four initial (T1) and final (T2) cephalometric film radiographs were obtained. Cranial base and regional superimpositions were completed independently for each pair of radiographs by either hand tracing and digital methods. To quantitatively evaluate the differences between the two methods, the hand and digital superimpositions were digitized to obtain x-y coordinates of routine cephalometric landmarks at T2. Linear distance between multiple corresponding (hand and digital) T2 cephalometric landmark locations (e.g., A point) were measured and defined as the T2 landmark distance (T2 LD). Additionally, 61 patient records were used to compare the digital method for best-fit cranial base superimpositions versus S-N superimpositions. A Friedman test was applied to examine for differences. Results: The upper 95% confidence limit for the mean of the T2 LD for hand and digital superimposition methods was <1 mm for all landmarks except maxillary incisor tip and apex. The upper 95% confidence interval for best-fit vs S-N was >1 mm for most landmarks. Conclusion: This study validates the use of superimpositions produced by Dolphin Imaging version 10 and is a necessary step forward toward widespread acceptance of digital superimpositions.

Download Full-text

Molecular Encapsulation of Herbicide Terbuthylazine in Native and Modifiedβ-Cyclodextrin

Journal of Chemistry ◽

10.1155/2017/8120367 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

E. Manuela Garrido ◽

Daniela Rodrigues ◽

Nuno Milhazes ◽

Fernanda Borges ◽

Jorge Garrido

Keyword(s):

Water Solubility ◽

Analytical Techniques ◽

Aqueous Solubility ◽

Mean Values ◽

H Nmr ◽

Nmr Data ◽

Kneading Method ◽

Other Substances ◽

The Mean ◽

The Stability

The herbicide terbuthylazine (TBA) is widely used for preemergence or postemergence control of many grass and broadleaf weeds and has, besides other issues, a poor aqueous solubility profile that results in reduced bioavailability. Cyclodextrins and modified cyclodextrins were considered, among other substances, appropriate agents for improving pesticide water solubility. Therefore, the inclusion complex formation of terbuthylazine withβ-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) was studied to attain its aqueous solubility enhancement. Their characterization was accomplished with different analytical techniques, namely, by UV-Vis, DSC, FTIR, and1H NMR. From the analysis of the complexation performance of the herbicide it was concluded that the interaction of terbuthylazine with CDs leads to the formation of inclusion complexes with a stoichiometry of 1 : 1. The association constants of the TBA/β-CD and TBA/HP-β-CD complexes were determined by UV. The mean values obtained for the stability constants are 460.4 ± 26.5 and 532.1 ± 27.6 to TBA/β-CD and TBA/HP-β-CD, respectively.1H NMR data corroborate the formation of the TBA/β-CD and TBA/HP-β-CD complexes synthesized by the kneading method. A formulation incorporating TBA cyclodextrin complexes might lead to an improvement in terbuthylazine bioavailability. The development of TBA-CD formulations may be interesting since it would enable, through their inclusion into the hydrophobic cavity of CDs, enhancement of solubility, bioavailability, and stability of the herbicide.

Download Full-text