Towards combined optical coherence tomography and multi-spectral imaging with MHz a-scan rates for endoscopy

We demonstrate a preliminary setup of a combined MHz-OCT and RGB narrowband reflection microscope and investigate the performance of the new RGB branch and different display modes of colored OCT data sets

Reportage fra Merapi - indonesisk vulkan i udbrud

Geologen Tom Pfeiffer havde det held at være ved vulkanen Merapi i Indonesien, da den gik i udbrud i maj i år. Her er historien om hans jagt på et godt billede.

CRISPR-TSKO : a technique for efficient mutagenesis in specific cell types, tissues, or organs in Arabidopsis

Detailed functional analyses of many fundamentally important plant genes via conventional loss-of-function approaches are impeded by the severe pleiotropic phenotypes resulting from these losses. In particular, mutations in genes that are required for basic cellular functions and/or reproduction often interfere with the generation of homozygous mutant plants, precluding further functional studies. To overcome this limitation, we devised a clustered regularly interspaced short palindromic repeats (CRISPR)-based tissue-specific knockout system, CRISPR-TSKO, enabling the generation of somatic mutations in particular plant cell types, tissues, and organs. In Arabidopsis (Arabidopsis thaliana), CRISPR-TSKO mutations in essential genes caused well-defined, localized phenotypes in the root cap, stomatal lineage, or entire lateral roots. The modular cloning system developed in this study allows for the efficient selection, identification, and functional analysis of mutant lines directly in the first transgenic generation. The efficacy of CRISPR-TSKO opens avenues for discovering and analyzing gene functions in the spatial and temporal contexts of plant life while avoiding the pleiotropic effects of system-wide losses of gene function

Stereo-electronic control of reaction selectivity in short-chain dehydrogenases : decarboxylation, epimerization, and dehydration

Sugar nucleotide?modifying enzymes of the short-chain dehydrogenase/reductase type use transient oxidation?reduction by a tightly bound nicotinamide cofactor as a common strategy of catalysis to promote a diverse set of reactions, including decarboxylation, single- or double-site epimerization, and dehydration. Although the basic mechanistic principles have been worked out decades ago, the finely tuned control of reactivity and selectivity in several of these enzymes remains enigmatic. Recent evidence on uridine 5'-diphosphate (UDP)glucuronic acid decarboxylases (UDP-xylose synthase, UDPapiose/UDP-xylose synthase) and UDP-glucuronic acid-4epimerase suggests that stereo-electronic constraints established at the enzyme?s active site control the selectivity, and the timing of the catalytic reaction steps, in the conversion of the common substrate toward different products. The mechanistic idea of stereo-electronic control is extended to epimerases and dehydratases that deprotonate the Ca of the transient ketohexose intermediate. The human guanosine 5'-diphosphate (GDP)-mannose 4,6-dehydratase was recently shown to use a minimal catalytic machinery, exactly as predicted earlier from theoretical considerations, for the 0-elimination of water from the keto-hexose species

In my old home

Gift of Dr. Mary Jane Esplen.Piano vocal [instrumentation]You ask a real darkey whats the dearest place [first line]In my old home [first line of refrain]A flat [key]Andante moderato [tempo]Popular song [form/genre]House trees lake ; Henry Troy (photograph) [illustration]EF Pfeiffer N.Y. [graphic artist]Publisher's advertisement on inside front and back cover [note