Up to the present time the function and significance of the zona pellucida in the development of mammalian eggs has not been fully explained. Zona-free mouse eggs will develop in vitro from the 2-cell stage, or later, up to the blastocyst stage (Tarkowski, 1961; Mintz, 1962; Gwatkin, 1963). Single blastomeres isolated at the 2-cell (Mulnard, 1965), 4and 8-cell stage (Tarkowski & Wróblewska, 196...

BACKGROUND Studies comparing similar-sized species with disparate longevity may elucidate novel mechanisms that abrogate aging and prolong good health. We focus on the longest living rodent, the naked mole-rat. This mouse-sized mammal lives ~8 times longer than do mice and, despite high levels of oxidative damage evident at a young age, it is not only very resistant to spontaneous neoplasia but...

Up to the present time the function and significance of the zona pellucida in the development of mammalian eggs has not been fully explained. Zona-free mouse eggs will develop in vitro from the 2-cell stage, or later, up to the blastocyst stage (Tarkowski, 1961; Mintz, 1962; Gwatkin, 1963). Single blastomeres isolated at the 2-cell (Mulnard, 1965), 4and 8-cell stage (Tarkowski & Wróblewska, 196...

Research of unique features in exotic animal species often reveals unexpected biology and may even shed light on disease treatment. A recent paper by Tian et al. studies a long-lived, cancer-free rodent named the naked mole rat (Heterocephalus glaber) to understand the mechanism of cancer resistance. Previous work by the same group has suggested early contact inhibition (ECI) in the naked mole ...

There are known models of spherical gravitational collapse in which the collapse ends in a naked shell-focusing singularity for some initial data. If a massless scalar field is quantized on the classical background provided by such a star, it is found that the outgoing quantum flux of the scalar field diverges in the approach to the Cauchy horizon. We argue that the semiclassical approximation ...

There are non-radial null geodesics emanating from the shell focusing singularity formed at the symmetric center in a spherically symmetric dust collapse. In this article, assuming the self-similarity in the region filled with the dust fluid, we study these singular null geodesics in detail. We see the time evolution of the angular diameter of the central naked singularity and show that it migh...

Stalled replication forks occasionally collapse, leading to potentially catastrophic DNA double-strand breaks. Now, Toledo et al. (2013) reveal that fork breakage occurs when the pool of the single-strand DNA-binding protein RPA becomes exhausted. This study has important implications for the origin and treatment of cancers with high levels of replicative stress.

Some birds such as vultures, ostriches, and certain species of stork have naked necks. This unusual feature allows them to tolerate heat better in hot climates. And, for vultures, the absence of neck feathers helps them poke about the insides of carrion unimpeded. The fossil record provides no evidence that naked necks evolved in a common ancestor, leaving scientists to explore other avenues to...

The security of modern computer systems heavily depends on security tools, especially on antivirus software solutions. In the anti-malware research community, development of techniques for evading detection by antivirus software is an active research area. This has led to malware that can bypass or subvert antivirus software. The common strategies deployed include the use of obfuscated code and...