scholarly journals Charles Ernest Weatherburn

1976 ◽  
Vol 21 (1) ◽  
pp. 1-4 ◽  
Author(s):  
F. Gamblen
Keyword(s):  
Experimental Evidence ◽  
Classical Theory ◽  
Laws Of Nature ◽  
Principle Of Equivalence ◽  
Mathematical Difficulties

“I have received from Einstein himself a copy of his recent papers, and I shall always consider it an honour to have done so. But still I am at liberty to say that the theory does not impress me as holding the secret of the laws of nature. I feel much more disposed to trust the classical theory, modified perhaps so as to recognise the principle of equivalence. Einstein's theory is wonderful—wonderful in its complexity and in the mathematical difficulties overcome. Newton's is even more wonderful—wonderful in its simplicity and in its agreement with nearly all the experimental evidence of two and a half centuries. I cannot agree with those who would make nature more akin to the complex than to the simple.”

scholarly journals I. Identifications

1938 ◽  
Vol 165 (922) ◽  
pp. 313-332 ◽  
Keyword(s):  
Classical Theory ◽  
Equations Of Motion ◽  
Laws Of Nature ◽  
Mechanical Force ◽  
Magnetic Intensity ◽  
Field Equations ◽  
Physical Assumption ◽  
General Object ◽  
Definition Of ◽  
Magnetic Poles

1. The general object of the following papers is to ascertain what form the equations of electromagnetism take when derived on a purely kinematic basis. Maxwell’s theory is not assumed. The only physical assumption made, namely, that a system of moving charges conserves its energy (defined kinematically) when the accelerations of the charges vanish, is a very slight one and is certainly satisfied in classical electromagnetism, but the resulting equations and laws, whilst coinciding with the classical theory to a considerable extent, differ in certain essential particulars. This arises from the avoidance of the empirical laws and hypothetical assumptions from which Maxwell’s theory starts. In particular we avoid the formal inconsistency in the classical theory by which a magnetic intensity H is defined via the mechanical force on an isolated magnetic pole, yet isolated magnetic poles do not occur in the classical “theory of electrons”. In the present treatment a magnetic intensity is defined via the mechanical force on a moving “charged” particle, as an element entering into the calculation of such force. The general method is, adopting the dynamics constructed in previous papers on a purely kinematic basis (Milne 1936, 1937), to formulate equations of motion containing the next most general type of “external” force arising after “gravitational” forces have been dealt with. Such forces arise from the double differentiation of scalar “superpotentials”, but we do not lay down what form these scalars are to take. Instead we allow them to determine themselves, by imposing the single physical assumption above-mentioned, after the equation of energy has been derived. Once the scalar superpotentials have been so determined, their double differentiation yields symbols E, H, which are then compared with the empirical laws governing the interaction of “charges”; this allows us to identify the adopted definition of charge and the symbols E, H with the similar quantities occurring in the experimental formulation. Lastly, we derive the identities satisfied by the resulting E, H; these partly coincide with, and partly differ from, the “field equations” with which the classical theory starts, and thus we end with theorems which play the part of the “laws of nature” assumed at the outset in the classical theory.

scholarly journals Antimalarials inhibit hematin crystallization by unique drug–surface site interactions

2017 ◽  
Vol 114 (29) ◽  
pp. 7531-7536 ◽  
Author(s):  
Katy N. Olafson ◽  
Tam Q. Nguyen ◽  
Jeffrey D. Rimer ◽  
Peter G. Vekilov
Keyword(s):  
Experimental Evidence ◽  
Classical Theory ◽  
Surface Site ◽  
Crystal Surfaces ◽  
Time Resolved ◽  
Effective Inhibition ◽  
Poor Indicator ◽  
Action Step ◽  
Surface Observations

In malaria pathophysiology, divergent hypotheses on the inhibition of hematin crystallization posit that drugs act either by the sequestration of soluble hematin or their interaction with crystal surfaces. We use physiologically relevant, time-resolved in situ surface observations and show that quinoline antimalarials inhibit β-hematin crystal surfaces by three distinct modes of action: step pinning, kink blocking, and step bunch induction. Detailed experimental evidence of kink blocking validates classical theory and demonstrates that this mechanism is not the most effective inhibition pathway. Quinolines also form various complexes with soluble hematin, but complexation is insufficient to suppress heme detoxification and is a poor indicator of drug specificity. Collectively, our findings reveal the significance of drug–crystal interactions and open avenues for rationally designing antimalarial compounds.

scholarly journals From classical theory to spin 2 gravity

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Miroslav Pardy ◽  
Keyword(s):  
Classical Theory ◽  
Einstein Equations ◽  
Principle Of Equivalence ◽  
Simple Derivation ◽  
Einstein Theory ◽  
Massless Particles ◽  
Gravity Equations ◽  
The Way

We consider here the simple derivation of the Einstein equations by Fock. Then, we approach the way from the spin 1 fields to the spin 2 fields for massive and massless particles and we derive the gravity equations from this base. In conclusion, we discuss the principle of equivalence in classical Einstein theory and in the Schwinger spin 2 gravity

How do memory modules differentially contribute to familiarity and recollection?

2019 ◽  
Vol 42 ◽  
Author(s):  
Olya Hakobyan ◽  
Sen Cheng
Keyword(s):  
Recognition Memory ◽  
Experimental Evidence ◽  
Subjective Experience ◽  
Target Article ◽  
Memory Modules ◽  
Familiarity And Recollection ◽  
Memory Contents

Abstract We fully support dissociating the subjective experience from the memory contents in recognition memory, as Bastin et al. posit in the target article. However, having two generic memory modules with qualitatively different functions is not mandatory and is in fact inconsistent with experimental evidence. We propose that quantitative differences in the properties of the memory modules can account for the apparent dissociation of recollection and familiarity along anatomical lines.

Redox Reactions in Lipid Membranes as a Model for Primordial Energy-Conserving Systems

1997 ◽  
Vol 161 ◽  
pp. 437-442
Author(s):  
Salvatore Di Bernardo ◽  
Romana Fato ◽  
Giorgio Lenaz
Keyword(s):  
Experimental Evidence ◽  
Lipid Membranes ◽  
Energy Supply ◽  
Redox Reactions ◽  
Living Systems ◽  
Asymmetric Distribution ◽  
Conservation Of Energy ◽  
Asymmetrical Distribution ◽  
Energy Conserving ◽  
Living Organisms

AbstractOne of the peculiar aspects of living systems is the production and conservation of energy. This aspect is provided by specialized organelles, such as the mitochondria and chloroplasts, in developed living organisms. In primordial systems lacking specialized enzymatic complexes the energy supply was probably bound to the generation and maintenance of an asymmetric distribution of charged molecules in compartmentalized systems. On the basis of experimental evidence, we suggest that lipophilic quinones were involved in the generation of this asymmetrical distribution of charges through vectorial redox reactions across lipid membranes.

A Method for Setting the Clearance Angle

1972 ◽  
Vol 30 ◽  
pp. 388-389
Author(s):  
Michael T. Bucek ◽  
Howard J. Arnott
Keyword(s):  
Experimental Evidence ◽  
Light Source ◽  
Black Spot ◽  
Critical Factor ◽  
Clearance Angle ◽  
Crude Approximation ◽  
Ultrathin Sections

It is believed by the authors, with supporting experimental evidence, that as little as 0.5°, or less, knife clearance angle may be a critical factor in obtaining optimum quality ultrathin sections. The degree increments located on the knife holder provides the investigator with only a crude approximation of the angle at which the holder is set. With the increments displayed on the holder one cannot set the clearance angle precisely and reproducibly. The ability to routinely set this angle precisely and without difficulty would obviously be of great assistance to the operator. A device has been contrived to aid the investigator in precisely setting the clearance angle. This device is relatively simple and is easily constructed. It consists of a light source and an optically flat, front surfaced mirror with a minute black spot in the center. The mirror is affixed to the knife by placing it permanently on top of the knife holder.

Introductory Remarks

1980 ◽  
Vol 38 ◽  
pp. 598-599
Author(s):  
H. Mohri
Keyword(s):  
Muscle Contraction ◽  
Experimental Evidence ◽  
Sea Urchin ◽  
Constant Length ◽  
Thin Filaments ◽  
Bridge Formation ◽  
Thick Filaments ◽  
Sliding Mechanism ◽  
Radial Spokes ◽  
Cilia And Flagella

In 1959, Afzelius observed the presence of two rows of arms projecting from each outer doublet microtubule of the so-called 9 + 2 pattern of cilia and flagella, and suggested a possibility that the outer doublet microtubules slide with respect to each other with the aid of these arms during ciliary and flagellar movement. The identification of the arms as an ATPase, dynein, by Gibbons (1963)strengthened this hypothesis, since the ATPase-bearing heads of myosin molecules projecting from the thick filaments pull the thin filaments by cross-bridge formation during muscle contraction. The first experimental evidence for the sliding mechanism in cilia and flagella was obtained by examining the tip patterns of molluscan gill cilia by Satir (1965) who observed constant length of the microtubules during ciliary bending. Further evidence for the sliding-tubule mechanism was given by Summers and Gibbons (1971), using trypsin-treated axonemal fragments of sea urchin spermatozoa. Upon the addition of ATP, the outer doublets telescoped out from these fragments and the total length reached up to seven or more times that of the original fragment. Thus, the arms on a certain doublet microtubule can walk along the adjacent doublet when the doublet microtubules are disconnected by digestion of the interdoublet links which connect them with each other, or the radial spokes which connect them with the central pair-central sheath complex as illustrated in Fig. 1. On the basis of these pioneer works, the sliding-tubule mechanism has been established as one of the basic mechanisms for ciliary and flagellar movement.

Sign in / Sign up

Export Citation Format

Share Document