scholarly journals A QUANTITATIVE MODEL FOR NONRANDOM GENERALIZED TRANSDUCTION, APPLIED TO THE PHAGE P22–SALMONELLA TYPHIMURIUM SYSTEM

Genetics ◽  
1986 ◽  
Vol 114 (2) ◽  
pp. 633-657
Author(s):  
W Mandecki ◽  
K Krajewska-Grynkiewicz ◽  
T Klopotowski
Keyword(s):  
Salmonella Typhimurium ◽  
Quantitative Model ◽  
Precise Determination ◽  
Standard Errors ◽  
Algebraic Equations ◽  
Phage P22 ◽  
The Mean ◽  
Number Of Classes ◽  
Generalized Transduction

ABSTRACT A mathematical model for nonrandom generalized transduction is proposed and analyzed. The model takes into account the finite number of transducing particle classes for any given marker. The equations for estimation of the distance between markers from cotransduction frequency data are derived and standard errors of the estimates are given. The obtained relationships depend significantly on the number of classes of transducing fragments. The model was applied to estimate the number of transducing fragment classes for a given marker in transduction with phage P22 of Salmonella typhimurium. It was found that the literature data on frequencies of cotransduction in crosses with mutual substitution of selective and nonselective markers can be rationalized most accurately by assuming that the mean number of classes is equal to 2. An improved method for analysis of cotransduction data is proposed on the basis of our model and the results of calculation. The method relies on solving a set of algebraic equations for cotransduction frequencies of markers located within one phage length. The method allows a relatively precise determination of distances between markers, positions of transducing particle ends and deletion or insertion lengths. The approach is applied to the trp-cysB-pyrF and aroC-hisT-purF-dhuA regions of the Salmonella typhimurium chromosome.

scholarly journals Hipparcos, Three Years After Launch

1993 ◽  
Vol 156 ◽  
pp. 1-10
Author(s):  
J. Kovalevsky ◽  
M. Froeschlé
Keyword(s):  
Standard Error ◽  
Present Status ◽  
Double Star ◽  
New Method ◽  
Standard Errors ◽  
First Year ◽  
Mass Determination ◽  
Mission Duration ◽  
The Mean

In a first part, the present status of the HIPPARCOS mission is described. Despite the degradations and failures of gyroscopes, it is still hoped that a 4 1/2 mission duration will be reached. The first-year of data has been reduced by both FAST and NDAC consortia. For the best 46200 observed stars, the distribution of standard errors in positions has a maximum of 1.5 mas in latitude and 1.8 mas in longitude and the mean standard error for parallaxes is of the order of 3 mas. The comparison of results obtained by both consortia shows that the differences are small and quite consistent with the announced internal precisions. Magnitude measurements are precise to 0.02 magnitude for a 4 second observation. The precision to be expected for double star observations is also given. The main new result is that the magnitudes of the components are obtained with a few hundredths of a magnitude precision. This allows to devise a new method of mass determination based upon the parallax and a recalibrated mass-luminosity diagram. The parallax dependence of the results is much more favourable than in the case of the classical determination of masses using orbital motions.

scholarly journals Station correction analysis for surface-wave magnitudes of New Zealand earthquakes

1999 ◽  
Vol 32 (1) ◽  
pp. 21-29 ◽  
Author(s):  
D. A. Rhoades ◽  
D. J. Dowrick
Keyword(s):  
New Zealand ◽  
Surface Wave ◽  
Linear Model ◽  
World Wide ◽  
Vertical Component ◽  
Horizontal Component ◽  
Standard Errors ◽  
Station Correction ◽  
The Mean

Station terms and standard errors are presented for 345 world-wide stations used in the determination of surface-wave magnitudes of 190 selected New Zealand earthquakes over the period 1901-1993 [1]. These will facilitate the estimation of surface-wave magnitudes of other earthquakes in the New Zealand region. The station terms and the residuals from the linear model used to estimate them are both found to be weakly related to the mean distance from the earthquakes recorded by each station. The horizontal and vertical components at a given site are treated as separate stations. The station term for the horizontal component tends to exceed that for the vertical component at mean distances in the 20°-40° range.

Generalized transduction by phage P22 in Salmonella typhimurium

1972 ◽  
Vol 71 (2) ◽  
pp. 433-448 ◽  
Author(s):  
Judith Ebel-Tsipis ◽  
David Botstein ◽  
Maurice S. Fox
Keyword(s):  
Salmonella Typhimurium ◽  
Phage P22 ◽  
Generalized Transduction

scholarly journals Cycloplegic Effects on the Cylindrical Components of the Refraction

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Athar Zareei ◽  
Milad Abdolahian ◽  
Shahram Bamdad
Keyword(s):  
Precise Determination ◽  
Lower Amount ◽  
Healthy Individuals ◽  
Male And Female ◽  
Near Vision ◽  
Before And After ◽  
The Mean ◽  
The Right ◽  
Age Range

It is important to predict which astigmatic patients require separate refraction for near vision. This study compared cylindrical components changes by cyclopentolate 1% for the low and high amount of astigmatism. The right eyes of 1014 healthy individuals (307 males and 707 females) with cylindrical refractive power more than −0.5 diopter on autorefractometer were selected. Both male and female patients in the age range of 17–45 years were refracted before and after cycloplegia, using 1% cyclopentolate. All volunteers were classified into 2 subgroups including the lower astigmatism group (−2.25 to −0.50) and the higher astigmatic group (−2.50 to over). Alpines’ method was used to compare the effect of cycloplegic drop on cylindrical power. The mean age in the lower astigmatism group (29.58; 95% CI: 29.18 to 29.99 years) was not significantly different from the higher astigmatic group (29.85; 95% CI: 29.07 to 30.62) and there were no significant differences in gender between these two groups ( P = 0.54 ). Differences between wet and dry refraction in J0 (−0.03; 95% CI:−0.06 to −0.008) and J45 (−0.03; 95% CI:−0.06 to −0.01) were significant only in the higher astigmatic group. Axis changes by the cycloplegic drop in the lower astigmatism group were 3.51 (CI: 3.22 to 3.81) and axis changes by the cycloplegic drop in the higher astigmatism group were 2.21 (CI: 1.73 to 2.49). In patients with a lower amount of astigmatism (−2.25 to −0.50), additional near subjective refraction could be done for precise determination of axis and in patients with a higher amount of astigmatism (−2.50 to over), near subjective refraction might be done for precise determination of power.

scholarly journals OSTEOMETRIC ANALYSIS OF SUPRAORBITAL FORAMEN AND NOTCH IN MALAYSIAN CRANIA

2019 ◽  
pp. 347
Author(s):  
ABDELNASSER IBRAHIM ◽  
SOHAYLA M ATTALLA ◽  
ASPALILAH ALIAS ◽  
MOHAMED SWARHIB ◽  
SITI NOORAIN ABU BAKAR ◽  
...  
Keyword(s):  
Anatomical Variations ◽  
Precise Determination ◽  
Reference Points ◽  
Transverse Diameter ◽  
Horizontal Diameter ◽  
Anatomical Classification ◽  
The Mean ◽  
Supraorbital Foramen

Objective: A clear knowledge of the location of supraorbital foramen (SOF) is vital for the surgeons, particularly in endoscopic surgery and regional block in crania. The aim of this study was to analyze SOF and notch in skulls of various ancestries. Methods: The anatomical variations of SOF and notch were examined in 100 adults skulls (55 males and 45 females) of the Malay, Chinese, and Indian ancestries by traditional measurement made with the Osirix software. The parameters included distance between supraorbital structure and nasal midline, shape, and transverse diameter of the SOF. Results: It was manifested that bilateral supraorbital notch (SON) was the most prevalent combination in both sexes and ancestries (61%), while combined SON and foramen (11%) were the least prevalent characteristic. The mean distances of supraorbital structure from nasal midline bilaterally in males were slightly greater than females. The horizontal diameter of SOF, notch and their distances from the nasal midline showed no difference between ancestries. Conclusion: This study would serve as a guide for the surgeons when surgery is performed on the scalp. It can help in the precise determination of reference points for supraorbital nerve blockade for the Malaysians. In addition, the variations exhibited in supraorbital measurements inevitably revealed that sex and ancestry should be taken into consideration when choosing samples for anatomical classification of crania.

scholarly journals OSTEOMETRIC ANALYSIS OF SUPRAORBITAL FORAMEN AND NOTCH IN MALAYSIAN CRANIA

2018 ◽  
Vol 11 (10) ◽  
pp. 509 ◽  
Author(s):  
Abdelnasser Ibrahim ◽  
Sohayla M Attalla ◽  
Aspalilah Alias ◽  
Mohamed Swarhib ◽  
Siti Noorain Abu Bakar ◽  
...  
Keyword(s):  
Anatomical Variations ◽  
Precise Determination ◽  
Reference Points ◽  
Transverse Diameter ◽  
Horizontal Diameter ◽  
Anatomical Classification ◽  
The Mean ◽  
Supraorbital Foramen

Objective: A clear knowledge of the location of supraorbital foramen (SOF) is vital for the surgeons, particularly in endoscopic surgery and regional block in crania. The aim of this study was to analyze SOF and notch in skulls of various ancestries.Methods: The anatomical variations of SOF and notch were examined in 100 adults skulls (55 males and 45 females) of the Malay, Chinese, and Indian ancestries by traditional measurement made with the Osirix software. The parameters included distance between supraorbital structure and nasal midline, shape, and transverse diameter of the SOF.Results: It was manifested that bilateral supraorbital notch (SON) was the most prevalent combination in both sexes and ancestries (61%), while combined SON and foramen (11%) were the least prevalent characteristic. The mean distances of supraorbital structure from nasal midline bilaterally in males were slightly greater than females. The horizontal diameter of SOF, notch and their distances from the nasal midline showed no difference between ancestries.Conclusion: This study would serve as a guide for the surgeons when surgery is performed on the scalp. It can help in the precise determination of reference points for supraorbital nerve blockade for the Malaysians. In addition, the variations exhibited in supraorbital measurements inevitably revealed that sex and ancestry should be taken into consideration when choosing samples for anatomical classification of crania.

XIX. On the mean density of the Earth

1821 ◽  
Vol 111 ◽  
pp. 276-292 ◽  
Keyword(s):  
Precise Determination ◽  
The Other ◽  
The Earth ◽  
The Mean ◽  
Whole Earth

Although the determination of the mean density of the whole terraqueous globe of our planet, is admitted to be a problem of the utmost importance to several branches of philosophy, particularly to physical astronomy, and the figure and constitution of the earth; it would seem, from the dis­cordancy of the declared opinions of some eminent philoso­phers, that the problem is still in an uncertain state. Since the first notice of this subject by Newton, in his admirable Principia, it has often been incidentally alluded to, without receiving a precise determination; with the exception of two instances only, in which it has been stated to be, certainly or approximately, determined by experiment; namely, in the case of the Schehallien experiment, by Dr. Maskelyne and myself, and by the Honorable Henry Cavendish, by a method invented by Mr. Michell. The former of these experiments was made by Dr. Maskelyne, in the years 1774, 1775, and 1776, by means of that large mountain in Scotland, in measuring its dimensions, and in comparing its attraction on a plummet, with that of the whole earth on the same; the calculations on it having been made by myself, and first published in the Philoso­phical Transactions of the year 1778; and since more correctly in the second volume of my Mathematical Tracts. The other experiment, by Mr. Cavendish, was by observing the attraction on small pendulous balls, of two inches di­ameter, by larger ones of ten inches diameter, as compared with the attraction of the earth on the same.

scholarly journals A Precise Determination of Some Critical Terms in the Solar System

1979 ◽  
Vol 81 ◽  
pp. 91-93
Author(s):  
Jean Chapront ◽  
Rudolf Dvorak
Keyword(s):  
Perturbation Theory ◽  
Solar System ◽  
High Precision ◽  
Precise Determination ◽  
Small Divisors ◽  
The Mean ◽  
New Form ◽  
Very High

A new form to determine the contribution of some special small divisors in perturbation theory is presented in this paper. We can avoid to calculate all the kλ+k′λ as it has to be done normally (λ and λ′ designate the mean longitudes of the two regarded planets). For a chosen k and k′ we calculate with a very high precision the contribution to the perturbation of the elements with the aid of the Hansen's coefficients.

scholarly journals Determination of Data Quality and Results from two Mount Hopkins Robotic Telescopes

1993 ◽  
Vol 136 ◽  
pp. 198-204 ◽  
Author(s):  
Diane M. Pyper ◽  
S.J. Adelman ◽  
R.J. Dukes ◽  
G.P. McCook ◽  
M.A. Seeds
Keyword(s):  
Standard Deviation ◽  
Preliminary Data ◽  
Standard Errors ◽  
Star Data ◽  
Robotic Telescopes ◽  
The Mean ◽  
Scientific Results ◽  
Bad Data ◽  
The Phoenix

AbstractWe present various methods for determining night quality from observations obtained with totally unattended automatic photoelectric telescopes at the Fairborn Observatory site on Mt. Hopkins, AZ. Telescopes are the Phoenix 10-inch (P10) and the Four College 75-cm (CAPT). Filter systems used are Johnson UBV, Kron-Cousins RI and Strömgren uvby. As a preliminary data filter for the P10 “rent-a-star” data, all observations with standard errors of the mean (SEM) above 20 mmag are discarded; a summary of nightly SEM’s, number of aborts and total observing time is sent to each user. The CAPT data are evaluated by standard deviation of magnitudes or counts for photometric groups and for an entire night. The Geneva photometric statistics are computed for these latter data and have proved useful as a preliminary screen for bad data. Various criteria for good and bad groups and nights are discussed. Scientific results are presented for several magnetic CP stars that were observed using both telescopes. Differences in precision of the data and strategies for observing are discussed.

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