Darkness serves as a stimulus for vertebrate photoreceptors; they are actively depolarized in the dark and hyperpolarize in the light. Here, we show that larval zebrafish essentially turn off their visual system at night when they are not active. Electroretinograms recorded from larval zebrafish show large differences between day and night; the responses are normal in amplitude throughout the d...

Uniquely in the world of materials, polymers deformed at high temperature and subsequently quenched at low temperature, memorize the temperature at which they have been processed. Polymers can even memorize multiple temperatures. This temperature memory is reflected by a maximum of residual stress restored at the temperature of initial processing. It has been speculated that this capability cou...

Telomeres in ageing and cancer Capping of chromosome ends is essential for the stability of linear chromosomes. It requires a minimum length of telomeric DNA, which can be synthesized and elongated by the enzyme telomerase. In addition, functional telomeres depend on the coordinated expression of a group of proteins that bind to telomeric DNA. These proteins are known as components of the shelt...

Like a tourist without a map, tumor-fighting T cells have a hard time finding their destination without directions. According to Clark et al. (page 2221), dismantling these directions helps skin cancer cells hide from killer T cells. To enter the skin, T cells must grab on to the adhesive molecule E-selectin, which is expressed on the endothelial cells lining blood vessels in the skin. The auth...

By David N. Gans, MSHA, FACMPE, vice president, MGMAACMPE Innovation and Research, [email protected] In the mid-1990s, many hospital systems adopted strategic plans that included hiring physicians or purchasing medical groups to build vertically integrated delivery systems (IDSs) of providers and locations of care. This strategy worked well for many health systems, but others hemorrhaged money. By t...

A b-skeleton is a proximity graphs with node neighbourhood defined by continuous-valued parameter b. Two nodes in a b-skeleton are connected by an edge if their lune-based neighbourhood contains no other nodes. With increase of b some edges a skeleton are disappear. We study how a number of edges in b-skeleton depends on b. We speculate how this dependence can be used to discriminate between ra...

A β-skeleton is a proximity graphs with node neighbourhood defined by continuousvalued parameter β. Two nodes in a β-skeleton are connected by an edge if their lune-based neighbourhood contains no other nodes. With increase of β some edges a skeleton are disappear. We study how a number of edges in β-skeleton depends on β. We speculate how this dependence can be used to discriminate between ran...

A detailed study of the mechanism by which a proton is lost from a dication reveals that such processes are more complicated than is often assumed. In many cases, a deprotonation reaction is best viewed as a two-stage process: Initially, the departing unit is better described as a hydrogen atom than as a proton and only later, at some point further along the decomposition pathway, does a sponta...

Most of the native forests in Argentina are used for livestock production with little sustainable silvopastoral management. Our objective here is to discuss different management strategies where natural and human capital combined co-produce ecosystem services (ES) provided by systems forests, interacting functions biodiversity. Also, we provide perspectives that should be analyzed a context soc...