The McMurdo Dry Valleys of Antarctica are a unique environment characterized by extreme lows in temperature and precipitation, which supports a low diversity microbial and multicellular fauna and flora. Terrestrial biomass is largely limited to soil microbes and mosses, while perennially ice-covered lakes host aerobic and anaerobic microbial communities, algae, and a low diversity eukaryotic fa...

analysis showed the presence of complex compounds containing calcium silicate hydrate in the synthesized sorbents.

All metazoan animals comprise a body plan of different complexity. Since--especially based on molecular and cell biological data--it is well established that all metazoan phyla, including the Porifera (sponges), evolved from a common ancestor the search for common, basic principles of pattern formation (body plan) in all phyla began. Common to all metazoan body plans is the formation of at leas...

PERRIERITE and chevkinite are rare R E E T i silicates reported from granitic and syenitic pegmatites and igneous rocks, volcanic ash beds, ignimbrites, and anorthosite (e.g. Jaffe et al., 1956; Young and Powers, 1960; Mitchell, 1966; Izett and Wilcox, 1968; Raade, 1970; Brooks and Rucklidge, 1976; Segalstad and Larsen, 1978; McDowell, 1979; Harding et al., 1982). The minerals are easily confus...

The giant basal spicule of the hexactinellid sponge Monorhaphis chuni represents the longest natural siliceous structure on Earth. This spicule is composed of concentrically arranged lamellae that are approximately 10 μm thick. In the present study, we investigated the formation of outer lamellae on a cellular level using microscopic and spectroscopic techniques. It is shown that the formation ...

The interfacial transition zone (ITZ) is known to strongly influence the mechanical and transport properties of mortars and concretes. This paper studies the ITZ between siliceous (quartz) aggregates and alkali-activated slag (AAS) binders in the context of mortar specimens. Backscattered electron (BSE) images generated in an environmental scanning electron microscope (ESEM) are used to identif...

Analysis of siliceous microfossils of a 79 cm long peat sediment core from Highlands Hammock State Park, Florida, revealed distinct changes in the local hydrology during the past 2,500 years. The coring site is a seasonally inundated forest where water availability is directly influenced by precipitation. Diatoms, chrysophyte statospores, sponge remains and phytoliths were counted in 25 samples...

A rapid and facile synthesis of cubic MCM-48 mesoporous material based on the modification of Stöber synthesis in as little time as 30 minutes at room temperature is reported in this communication.