The Effects of the 1906 Earthquake in California on Research and Education

2006 ◽  
Vol 22 (2_suppl) ◽  
pp. 207-236 ◽  
Author(s):  
Robert Reitherman
Keyword(s):  
Historical Review ◽  
The Other ◽  
Great Earthquake ◽  
Final Conclusion ◽  
Seismic Safety ◽  
Earthquake Research ◽  
A Chain ◽  
Research And Education ◽  
Education Effects ◽  
First And Second Generation

The great earthquake that struck on 18 April 1906 and caused a disaster also forged the first link in a chain of research and education effects that extended over the following decades. Now, with a century of hindsight, we have an advantageous point from which to view that earthquake and the developments it parented. We also face two disadvantages. One is that first-hand accounts and obscure documents are either lost or hard to find. The other is that while the centennial of the earthquake has prompted celebration and promotion activities, however appropriate they may be for advancing seismic safety, a different attitude is required for an objective historical review. The research reported here was conducted within such a critical frame of mind, but the final conclusion is not that the research and education impacts of the 1906 earthquake are overrated. Rather, several unacknowledged developments stemming from the earthquake are brought to light. While the first- and second-generation effects constituted a wave of influence that has largely passed by a century later, the tide today in the earthquake research and education field is still persistently higher than it would be if the 1906 earthquake had not occurred.

scholarly journals XXIII.—On the Disruptive Discharge of Electricity: An Experimental Thesis for the Degree of Doctor of Science, Department A

1878 ◽  
Vol 28 (2) ◽  
pp. 633-671 ◽  
Author(s):  
Alexander Macfarlane
Keyword(s):  
Copper Wire ◽  
Late Summer ◽  
The Other ◽  
Straight Line ◽  
Summer Session ◽  
The Difference ◽  
A Chain ◽  
The One ◽  
Metallic Parts ◽  
The University

The experiments to which I shall refer were carried out in the physical laboratory of the University during the late summer session. I was ably assisted in conducting the experiments by three students of the laboratory,—Messrs H. A. Salvesen, G. M. Connor, and D. E. Stewart. The method which was used of measuring the difference of potential required to produce a disruptive discharge of electricity under given conditions, is that described in a paper communicated to the Royal Society of Edinburgh in 1876 in the names of Mr J. A. Paton, M. A., and myself, and was suggested to me by Professor Tait as a means of attacking the experimental problems mentioned below.The above sketch which I took of the apparatus in situ may facilitate tha description of the method. The receiver of an air-pump, having a rod capable of being moved air-tight up and down through the neck, was attached to one of the conductors of a Holtz machine in such a manner that the conductor of the machine and the rod formed one conducting system. Projecting from the bottom of the receiver was a short metallic rod, forming one conductor with the metallic parts of the air-pump, and by means of a chain with the uninsulated conductor of the Holtz machine. Brass balls and discs of various sizes were made to order, capable of being screwed on to the ends of the rods. On the table, and at a distance of about six feet from the receiver, was a stand supporting two insulated brass balls, the one fixed, the other having one degree of freedom, viz., of moving in a straight line in the plane of the table. The fixed insulated ball A was made one conductor with the insulated conductor of the Holtz and the rod of the receiver, by means of a copper wire insulated with gutta percha, having one end stuck firmly into a hole in the collar of the receiver, and having the other fitted in between the glass stem and the hollow in the ball, by which it fitted on to the stem tightly. A thin wire similarly fitted in between the ball B and its insulating stem connected the ball with the insulated half ring of a divided ring reflecting electrometer.

scholarly journals The linkage of sugar phosphate polymer to peptidoglycan in walls of Micrococcus sp. 2102

1978 ◽  
Vol 169 (2) ◽  
pp. 329-336 ◽  
Author(s):  
J Heptinstall ◽  
J Coley ◽  
P J Ward ◽  
A R Archibald ◽  
J Baddiley
Keyword(s):  
Staphylococcus Aureus ◽  
Alkaline Hydrolysis ◽  
The Other ◽  
Muramic Acid ◽  
Sugar Phosphate ◽  
Glycerol Phosphate ◽  
Homogeneous Product ◽  
A Chain

1. Protein-free walls of Micrococcus sp. 2102 contain peptidoglycan, poly-(N-acetylglucosamine 1-phosphate) and small amounts of glycerol phosphate. 2. After destruction of the poly-(N-acetylglucosamine 1-phosphate) with periodate, the glycerol phosphate remains attached to the wall, but can be removed by controlled alkaline hydrolysis. The homogeneous product comprises a chain of three glycerol phosphates and an additional phosphate residue. 3. The poly-(N-acetylglucosamine 1-phosphate) is attached through its terminal phosphate to one end of the tri(glycerol phosphate). 4. The other end of the glycerol phosphate trimer is attached through its terminal phosphate to the 3-or 4-position of an N-acetylglucosamine. It is concluded that the sequence of residues in the sugar 1-phosphate polymer-peptidoglycan complex is: (N-acetylglucosamine 1-phosphate)24-(glycerol phosphate)3-N-acetylglucosamine 1-phosphate-muramic acid (in peptidoglycan). Thus in this organism the phosphorylated wall polymer is attached to the peptidoglycan of the wall through a linkage unit comprising a chain of three glycerol phosphate residues and an N-acetylglucosamine 1-phosphate, similar to or identical with the linkage unit in Staphylococcus aureus H.

NUMERICAL ANALYSIS OF RANDOM DRIFT IN A CLINE

Genetics ◽  
1980 ◽  
Vol 94 (2) ◽  
pp. 497-517
Author(s):  
Thomas Nagylaki ◽  
Bradley Lucier
Keyword(s):  
Natural Populations ◽  
The Other ◽  
Random Genetic Drift ◽  
Gene Frequencies ◽  
Random Drift ◽  
Linear Habitat ◽  
Asymptotic Formulae ◽  
A Chain ◽  
Average Position ◽  
Uniform Population

ABSTRACT The equilibrium state of a diffusion model for random genetic drift in a cline is analyzed numerically. The monoecious organism occupies an unbounded linear habitat with constant, uniform population density. Migration is homogeneouq symmetric and independent of genotype. A single diallelic locus with a step environment is investigated in the absence of dominance and mutation. The flattening of the expected cline due to random drift is very slight in natural populations. The ratio of the variance of either gene frequency to the product of the expected gene frequencies decreases monotonically to a nonzero constant. The correlation between the gene frequencies at two points decreases monotonically to zero as the separation is increased with the average position fixed; the decrease is asymptotically exponential. The correlation decreases monotonically to a positive constant depending on the separation as the average position increasingly deviates from the center of the cline with the separation fixed. The correlation also decreases monotonically to zero if one of the points is fixed and the other is moved outward in the habitat, the ultimate decrease again being exponential. Some asymptotic formulae are derived analytically.—The loss of an allele favored in an environmental pocket is investigated by simulating a chain of demes exchanging migrants, the other assumptions being the same as above. For most natural populations, provided the allele would be maintained in the population deterministically, this process is too slow to have evolutionary importance.

1. On the Philological Genius and Character of the Neo-Hellenic Dialect

1875 ◽  
Vol 8 ◽  
pp. 31-31
Author(s):  
Blackie
Keyword(s):  
Middle Ages ◽  
Present State ◽  
Historical Review ◽  
Popular Literature ◽  
The Other ◽  
Greek Language ◽  
Modern Language ◽  
The Past ◽  
History Of ◽  
Of Greece

The Author showed by a historical review of the fortunes of Greece, through the Middle Ages, and under the successive influences of Turkish conquest and Turkish oppression, how the Greek language had escaped corruption to the degree that would have caused the birth of a new language in the way that Italian and the other Roman languages grew out of Latin. He then analysed the modern language, as it existed in current popular literature before the time of Coraes, that is, from the time of Theodore Ptochoprodromus to nearly the end of the last century, and showed that the losses and curtailments which it had unquestionably suffered in the course of so many centuries, were not such as materially to impair the strength and beauty of the language, which in its present state was partly to be regarded as a living bridge betwixt the present and the past, and as an altogether unique phenomenon in the history of human speech.

Is Medical Informatics an Art or a Science?

2006 ◽  
Vol 45 (06) ◽  
pp. 651-655
Author(s):  
R. Haux ◽  
A. Hasman ◽  
A. T. McCray ◽  
J. van der Lei
Keyword(s):  
Medical Informatics ◽  
The Other ◽  
Special Topic ◽  
Research And Education

Summary Objective: To give an introduction to the special topic on ‘Medical Informatics: Art or Sciene?‘ in honor of Prof. Dr. Jan Hendrik van Bemmel. Method: Retrospective, personal review on his work. Results and Conclusions: Jan H. van Bemmel contributed exceptionally to research and education as well as to systematizing and promoting medical informatics. Details are provided in this and the other papers of this special topic of Methods of Information in Medicine.

scholarly journals Historical Review: Paroxysmal Nocturnal Hemoglobinuria

Blood ◽  
1951 ◽  
Vol 6 (3) ◽  
pp. 270-284 ◽  
Author(s):  
WILLIAM H. CROSBY
Keyword(s):  
19Th Century ◽  
Paroxysmal Nocturnal Hemoglobinuria ◽  
Case Reports ◽  
Historical Review ◽  
Great Accuracy ◽  
The Other ◽  
Disease Entity ◽  
History Of ◽  
The 19Th Century ◽  
Outstanding Work

Abstract 1. The history of paroxysmal nocturnal hemoglobinuria is reviewed, and attention is called to four case reports published in the 19th century. A bibliography of the disease is appended. 2. The outstanding work of Paul Strübing is reviewed. Strübing identified paroxysmal nocturnal hemoglobinuria as a disease entity in 1882 but failed to give it a distinctive name. He described the disease with great accuracy, calling particular attention to the part played by sleep in precipitating the paroxysms. He cited earlier reports of nocturnal hemoglobinuria and by provocative tests differentiated the disease from the other paroxysmal hemoglobinurias. On the basis of his observations he proposed theories regarding the pathogenesis of the disease which have now been shown to be remarkably accurate.

Influence of Hopf Bifurcation Dynamics on Conduction Failure of Action Potentials Along Nerve C-Fiber

2019 ◽  
Vol 29 (07) ◽  
pp. 1950093 ◽  
Author(s):  
Xinjing Zhang ◽  
Huaguang Gu
Keyword(s):  
Hopf Bifurcation ◽  
Coupling Strength ◽  
The Other ◽  
Dimensional Parameter ◽  
External Stimulation ◽  
C Fiber ◽  
Current Threshold ◽  
Stimulation Period ◽  
Conduction Failure ◽  
A Chain

Contrary to faithful conduction of every action potential or spike along the axon, some spikes induced by the external stimulation with a high frequency at one end of the unmyelinated nerve fiber (C-fiber) disappear during the conduction process to the other end, which leads to conduction failure. Many physiological functions such as information coding or pathological pain are involved. In the present paper, the dynamic mechanism of the conduction failure is well interpreted by two characteristics of the focus near Hopf bifurcation of the Hodgkin–Huxley (HH) model. One is that the current threshold to evoke a spike from the after-potential corresponding to the focus exhibits damping oscillations, and the other is that the damping oscillations exhibit an internal period. A chain network model composed of HH neurons and stimulated by the external periodic stimulation is used to stimulate C-fiber. In the two-dimensional parameter space of the stimulation period and coupling strength, the conduction failure appears for the coupling strength lower than that of the faithful conduction, which is due to some maximal values of the coupling current for low coupling strength not being strong enough to evoke spikes, and the coupling strength threshold between the faithful conduction and conduction failure exhibiting damping oscillations with respect to the stimulation period, due to the damping oscillations of the current threshold. The damping oscillations of the coupling strength exhibit close correlations to those of the current threshold. The coupling strength for the conduction failure exhibits maximal values as the stimulation period is approximated to 1-, 2-, 3- or 4-times of the internal period and the maximal values decrease with increasing stimulation period. In addition, the correspondence between the simulation results and the previous experimental observations is discussed. The results present deep insights into the dynamics of the conduction failure with Hopf bifurcation and are helpful to investigate the influence of other modulation factors on the conduction failure.

scholarly journals Evaluation of Three Ear Tag Formulations for Control of Flies on Beef Cattle, 1993

1994 ◽  
Vol 19 (1) ◽  
pp. 366-366
Author(s):  
R. W. Miller
Keyword(s):  
Beef Cattle ◽  
Untreated Control ◽  
The Other ◽  
Stable Flies ◽  
Angus Cattle ◽  
Mixed Breed ◽  
Cow Calf ◽  
Research And Education ◽  
Horn Flies

Abstract Three herds (36-122 head per herd) of Angus cattle (cow-calf or yearling heifers) located at the Wye Research and Education Center, Queenstown, MD, were tagged with one of three ear tag formulations. On 17 May one of the herds was tagged with Optimizer tags (2 per head) and on 2 Jun the other 2 herds were tagged with Python tags (2 per head) or experimental YT-615 tags (1 per head). A herd of mixed-breed beef cattle located approximately 4 km from the treated cattle served as an untreated control. Fly density was determined by making biweekly counts on 15 cattle in each of the herds. Counts were made ol face flies/face, horn flies/animal, and stable flies/4 legs. Two (Optimizer herd) or 3 (other 2 herds) pretreatment and 11 or 10 posttreatment counts were made.

DNA supercoiling and transcription: topological coupling of promoters

1996 ◽  
Vol 29 (3) ◽  
pp. 203-225 ◽  
Author(s):  
David M. J. Lilley ◽  
Dongrong Chen ◽  
Richard P. Bowater
Keyword(s):  
Fundamental Property ◽  
Dna Supercoiling ◽  
The Other ◽  
Linear Dna ◽  
Dna Molecule ◽  
Linking Number ◽  
Closed Circle ◽  
A Chain

DNA supercoiling is a consequence of the double-stranded nature of DNA. When a linear DNA molecule is ligated into a covalently closed circle, the two strands become intertwined like the links of a chain, and will remain so unless one of the strands is broken. The number of times one strand is linked with the other is described by a fundamental property of DNA supercoiling, the linking number (Lk).

scholarly journals On the semantics of place/transition Petri nets

1997 ◽  
Vol 7 (4) ◽  
pp. 359-397 ◽  
Author(s):  
JOSÉ MESEGUER ◽  
UGO MONTANARI ◽  
VLADIMIRO SASSONE
Keyword(s):  
Petri Nets ◽  
The Other ◽  
General Category ◽  
Monoidal Categories ◽  
Other Hand ◽  
Models Of Concurrency ◽  
A Chain ◽  
The One ◽  
Algebraic Domains

Place/transition (PT) Petri nets are one of the most widely used models of concurrency. However, they still lack, in our view, a satisfactory semantics: on the one hand the ‘token game’ is too intensional, even in its more abstract interpretations in terms of nonsequential processes and monoidal categories; on the other hand, Winskel's basic unfolding construction, which provides a coreflection between nets and finitary prime algebraic domains, works only for safe nets. In this paper we extend Winskel's result to PT nets. We start with a rather general category PTNets of PT nets, we introduce a category DecOcc of decorated (nondeterministic) occurrence nets and we define adjunctions between PTNets and DecOcc and between DecOcc and Occ, the category of occurrence nets. The role of DecOcc is to provide natural unfoldings for PT nets, i.e., acyclic safe nets where a notion of family is used to relate multiple instances of the same place. The unfolding functor from PTNets to Occ reduces to Winskel's when restricted to safe nets. Moreover, the standard coreflection between Occ and Dom, the category of finitary prime algebraic domains, when composed with the unfolding functor above, determines a chain of adjunctions between PTNets and Dom.

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