"Evidence concerning the absorption of light quanta by visual pigment molecules is used to derive a theoretical relationship between the parameters of light incident on the retina and the output of the receptor cells. This relationship leads to the following prediction: when two retinal areas are illuminated, one very intensely and the other still more intensely, there will be a period of time ...

Computer forensics has recently gained significant popularity with many local law enforcement agencies. It is currently employed in fraud, theft, drug enforcement and almost every other enforcement activity. The research paper includes the types of attempts to destroy or tamper the files by the culprits and unleashes various recovery techniques, and their significance in different situations fr...

to detect the earliest disease in the maximum number of patients at least cost to the community. In conclusion, there is offered an ideal community program of eradication of tuberculosis-a disease which still claims 60,000 deaths annually in the United States. This small volume is very readable, authoritative, and well documented. It offers much of interest-and a challenge-to all charged with t...

An a-L-fucosidase was purified approximately 600-fold from Clostridium perfringens; it is free of other glycosidases present in the crude extract. The fucosidase occurs in multiple “isozymic” forms with molecular weights greater than 200,000. It is an oc-(1 + 2)-specific L-fucosidase with action on oligosaccharides and glycoproteins, but with no action on simple methyl or nitrophenyl fucosides....

The observed cosmic abundances of light elements are most consistent with each other, and with the predictions of big bang nucleosynthesis, if, contrary to the usual assumption, galactic chemical evolution reduces (D + He)/H with time. Chemical evolution models which do this require that low mass stars destroy He in the envelope gas that they return to the interstellar medium. A simple argument...

This study was conducted to evaluate the effect of different extraction solvents, including hydro-alcoholic (H-A), ethanolic (Et-OH), and methanolic (Me-OH), on chemical composition and synergistic antibacterial activity of Frangula alnus extract against Staphylococcus aureus and Escherichia coli. The chemical composition of the F. alnus bark extract was eval...

The possibility of simultaneous opposite running thermodynamic arrows of time has been raised on several occasions, for didactic purposes [1], for general interest [2], and to confound by “obvious” counterexample [2]. A difficulty in these considerations is the absence of a welldefined framework. For example, one might argue against opposing arrows as follows. Let the systems be A and B. An obs...