Genetic, abiotic and social influences on sex differentiation in cichlid fishes and the evolution of sequential hermaphroditism

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73799/1/j.1467-2979.2005.00184.x.pd

Complex monolayer growth dynamics of a highly symmetric molecule NTCDA on Ag 111

The growth dynamics of the highly symmetric planar organic molecule NTCDA (1,4,5,6-naphthalene tetracarboxylic acid dianhydride) on Ag(111) is rather complex, already in the monolayer regime. This dynamics was investigated in situ with high lateral resolution using the aberration-corrected spectro-microscope SMART. Although the molecular structure of NTCDA is very similar to that of the slightly larger molecule PTCDA, the growth behavior of these two molecules is very different. Several differences of the static geometric, electronic, and vibrational structure have been described previously by several authors, but some dynamic properties hardly accessible by other techniques could be observed in the present real time experiments using the SMART. For instance, it is found by direct observation that after decoration of steps and step bunches and depending on substrate temperature and surface morphology, a two-dimensional lattice gas of diffusing NTCDA molecules is formed. This increases in density upon continuous deposition of molecules before islands nucleate which subsequently grow in size while the density of the lattice gas first remains constant and then is reduced. Furthermore, in a certain temperature and coverage range some macroscopic islands (of micrometer size) abruptly change their shape and position on the time scale of few seconds. These “jumping 2-dim droplets” are observable for adsorption as well as for desorption. Moreover, previously observed 2-dimensional phase transitions can now be followed in real time, yielding further insight into an interesting but complex adsorption system

Influence of Substrate Bonding and Surface Morphology on Dynamic Organic Layer Growth Perylenetetracarboxylic Dianhydride on Au 111

We investigated the dynamics of the initial growth of the first epitaxial layers of perylenetetracarboxylic dianhydride (PTCDA) on the Au(111) surface with high lateral resolution using the aberration-corrected spectro-microscope SMART. With this instrument, we could simultaneously study the different adsorption behaviors and layer growth on various surface areas consisting of either a distribution of flat (111) terraces, separated by single atomic steps (“ideal surface”), or on areas with a high density of step bunches and defects (“realistic surface”). The combined use of photoemission electron microscopy, low-energy electron microscopy, and μ-spot X-ray absorption provided a wealth of new information, showing that the growth of the archetype molecule PTCDA not only has similarities but also has significant differences when comparing Au(111) and Ag(111) substrate surfaces. For instance, under otherwise identical preparation conditions, we observed different growth mechanisms on different surface regions, depending on the density of step bunches. In addition, we studied the spatially resolved desorption behavior which also depends on the substrate morphology

Schlauchfolien aus Cellulose-Protein-Blends

WO 200145917 A UPAB: 20010927 NOVELTY - Oriented tubular films are manufactured by using a spinning solution comprising a homogeneous solution of a mixture of cellulose and protein(s) in an n-methylmorpholine-n-oxide (NMMO)-water system. DETAILED DESCRIPTION - Manufacture of oriented tubular films includes extrusion of a spinning solution using a ring nozzle over an external air gap into a precipitation bath. The spinning solution includes a homogeneous solution of a mixture of cellulose and protein(s) in NMMO-water system. The homogeneous solution is produced by withdrawing the water of the solution until both the cellulose and protein are dissolved completely. USE - The invention is used to manufacture oriented tubular films used as biodegradable and compostable packaging materials (claimed). Particularly, the films are used as sausage skins for hard sausages, and as peelable skins (claimed). ADVANTAGE - The invention provides strong and flexible tubular films, which make expensive after treatment or surface treatment unnecessary

On the magnetic properties of iron nanostructures fabricated via focused electron beam induced deposition and autocatalytic growth processes

We employ Electron beam induced deposition (EBID) in combination with autocatalytic growth (AG) processes to fabricate magnetic nanostructures with controllable shapes and thicknesses. Following this route, different Fe deposits were prepared on silicon nitride membranes under ultra-high vacuum conditions and studied by scanning electron microscopy (SEM) and scanning transmission x-ray microspectroscopy (STXM). The originally deposited Fe nanostructures are composed of pure iron, especially when fabricated via autocatalytic growth processes. Quantitative near-edge x-ray absorption fine structure (NEXAFS) spectroscopy was employed to derive information on the thickness dependent composition. X-ray magnetic circular dichroism (XMCD) in STXM was used to derive the magnetic properties of the EBID prepared structures. STXM and XMCD analysis evinces the existence of a thin iron oxide layer at the deposit-vacuum interface, which is formed during exposure to ambient conditions. We were able to extract magnetic hysteresis loops for individual deposits from XMCD micrographs with varying external magnetic field. Within the investigated thickness range (2-16 nm), the magnetic coercivity, as evaluated from the width of the hysteresis loops, increases with deposit thickness and reaches a maximum value of ∼160 Oe at around 10 nm. In summary, we present a viable technique to fabricate ferromagnetic nanostructures in a controllable way and gain detailed insight into their chemical and magnetic properties.Peer Reviewe