منابع مشابه
Vitality of optical vortices
Optical vortices are always created or annihilated in pairs with opposite topological charges. However, the presence of such a vortex dipole does not directly indicate whether they are associated with a creation or an annihilation event. Here we propose a method to distinguish between vortex dipoles that have just been created and those that are about to be annihilated. We use first and second ...
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Sperm vitality is a reflection of the proportion of live, membrane-intact spermatozoa determined by either dye exclusion or osmoregulatory capacity under hypo-osmotic conditions. In this chapter we address the two most common methods of sperm vitality assessment: eosin-nigrosin staining and the hypo-osmotic swelling test, both utilized in clinical Andrology laboratories.
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MANY OF those who share an interest in the life sciences today, perhaps most, would agree with the claim that vitalism is obsolete. Some prominent biologists now use ‘vitalism’ as a derogatory label associated with lack of intellectual rigour, anti-scientific attitudes, and superstition (see, e.g., Dawkins, 1988). Other scientific commentators treat the term more seriously, but equally arrive a...
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The fingerprint liveness detection refers to the inspection of the finger characteristics to ensure whether the input finger is live or artificial. A number of fingerprint identification systems are used widely and implemented at various important places such as border and immigration services. However, it is not declared by the manufacturers of these systems whether liveness detection is actua...
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We examine evidence supporting the associations among physical activity (PA), cognitive vitality, neural functioning, and the moderation of these associations by genetic factors. Prospective epidemiological studies provide evidence for PA to be associated with a modest reduction in relative risk of cognitive decline. An evaluation of the PA-cognition link across the life span provides modest su...
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ژورنال
عنوان ژورنال: Nature
سال: 1991
ISSN: 0028-0836,1476-4687
DOI: 10.1038/353022a0