Diode laser with 1 Hz linewidth.

We report an ultranarrow-linewidth laser spectrometer at 657 nm, consisting of a diode laser locked in a single stage to a stable high-finesse reference cavity. The system is characterized by comparison with a second independent system. From beat frequency measurements a linewidth below 1.5 Hz (FWHM) and a fractional instability of less than 2 x 10(-15) for 1 s of averaging time are observed.

Willet M. Hays, great benefactor to plant breeding and the founder of our association.

Willet M. Hays was a great benefactor to plant breeding and the founder of the American Genetic Association (AGA). We commemorate the AGA's centennial. We mined university archives, U.S. Department of Agriculture (USDA) yearbooks, plant breeding textbooks, scientific periodicals, and descendants for information. Willet Hays first recognized the individual plant as the unit of selection and started systematic pure-line selection and progeny tests in 1888. He developed useful plant breeding methods. He selected superior flax (Linum usitatissimum L.), wheat (Triticum vulgare L.), corn (Zea mays L.), barley (Hordeum vulgare L.), and oat (Avena sativa L.) varieties, and discovered Grimm alfalfa (Medicago sativa L.); all became commercially important. He initiated branch stations for better performance testing. Willet Hays befriended colleagues in other universities, in federal stations, in a London conference, and in Europe. He gathered and spread the scientific plant breeding gospel. He also improved rural roads and initiated animal breeding records and agricultural economics records. He started the AGA in 1903, serving as secretary for 10 years. He became assistant secretary of agriculture in 1904. He introduced the project system for agricultural research. He authored or coauthored the Nelson Amendment, the Smith-Lever Act, the Smith-Hughes Act, and the protocol leading to the United Nations Food and Agriculture Organization-all involved teaching agricultural practices that improved the world.

The frequent Marburg I polymorphism impairs the pro-urokinase activating potency of the factor VII activating protease (FSAP).

The recently reported plasmatic, Factor Seven Activating Protease (FSAP), has also been found to be a potent activator of pro-urokinase [single-chain plasminogen activator, urinary type (scuPA)]. An initial epidemiological study surprisingly showed that plasmas of 5-10% of healthy blood donors had an impaired potential to activate scuPA. Analysis of the respective genomic DNAs revealed one particular single nucleotide polymorphism of FSAP resulting in an identical amino acid exchange (G511E), which correlates with the reduced activities. The corresponding mutation was named FSAP Marburg I. Thrombelastographies of wild-type and mutant plasmas were performed, facilitating the auto-activation of the intrinsic FSAP pro-enzymes by addition of dextran sulfate (DXS) and accelerated clot lysis by addition of scuPA. On these conditions, tissue-factor-induced coagulation revealed that clot lysis was significantly delayed in the Marburg I mutant plasmas as compared with wild-type plasmas. Furthermore, in the presence of DXS and scuPA, a FSAP-deficient plasma revealed significantly prolonged plasma clot lysis times, whereas the addition of purified FSAP pro-enzyme plus scuPA reversed this effect. These results support the hypothesis that FSAP contributes to the scuPA-dependent plasma fibrinolytic potential, which can be impaired in plasmas containing the FSAP Marburg I polymorphism, for instance.

Identification of a novel retina-specific gene located in a subtelomeric region with polymorphic distribution among multiple human chromosomes.

The human retina is comprised of a large number of cell types with highly specialized functions that depend on the action of countless genes, many of which are exclusively expressed in the retina. We have isolated a novel retinal gene, termed F379. The transcript was initially identified as a cluster of ESTs derived predominantly from retinal cDNA libraries and its retinal transcription confirmed by Northern blot and RT-PCR. Screening of retinal cDNA libraries yielded four clones that were assembled into a 1188 bp consensus sequence. The putative open reading frame includes an unusual configuration of Alu and MIR repeats and encodes a putative 85 aa peptide with no significant homology to any known protein sequence outside of the Alu and MIR elements. Comparison with genomic sequence determined that F379 consists of three exons and maps to multiple locations throughout the genome, a finding confirmed by PCR screening of a somatic cell hybrid mapping panel. F379 appears to be contained within a region of subtelomeric DNA that is duplicated in a polymorphic distribution to multiple chromosomes. Comparison of interchromosomal sequence variation with the sequences of expressed transcripts suggests that the gene is transcribed in the human retina from at least four different chromosomes.

A sequence-ready high-resolution physical map of the best macular dystrophy gene region in 11q12-q13.

Best disease, an autosomal dominant inherited macular degenerative disorder, was previously localized between D11S1765 and UGB (uteroglobin) in 11q13 by genetic linkage analysis. Since this region was found to be refractory to cloning in YAC (yeast artificial chromosome)-based vectors, a P1 artificial chromosome (PAC) contig was assembled. Gridded PAC libraries representing a 16-fold genome equivalent were screened by hybridization using PCR products representing STSs derived from YAC end sequences, markers binned to 11q13, and PAC-derived insert ends. A highly marker dense approximately 1.7-Mb PAC contig that encompassed the disease gene region was constructed, allowing us to order accurately the markers throughout the region and to provide the most precise estimate of its physical size. Using this contig, thus far we have mapped seven anonymous ESTs and five known genes into this region. This high-resolution physical map will facilitate the isolation of polymorphic markers for refinement of the disease gene region, as well as the identification of candidate genes by exon trapping, cDNA selection, and gene prediction from PAC-derived genomic sequence.

Influence of different conditioning methods on force and fatigue resistance in chronically stimulated skeletal muscles.

A study was undertaken to compare different conditioning methods for the transformation of latissimus dorsi muscle into a fatigue resistant one for application in circulatory assist. In ten sheep four electrodes were sutured to the epineurium of the left thoracodorsal nerve for indirect electrical stimulation of the latissimus dorsi muscle. In six sheep a "carousel stimulation," a special multichannel stimulation, in combination with a recently developed conditioning protocol was used for muscle conditioning (multichannel method). In four sheep, a conventional stimulation protocol using single channel stimulation was applied for transformation of the muscle (single channel method). The final experiments were carried out when fatigue resistance was obtained. The maximum tetanic forces at different preloads were determined and fatigue resistance was tested during 20 minutes of continuous stimulation. Both conditioning patterns led to fatigue-free chronic stimulation. Muscles conditioned by multichannel stimulation exhibited between 20% and 33% less force than the contralateral unconditioned muscles, whereas in the single channel group this loss was between 32% and 43%. Thus, the multichannel method revealed relatively superior in preserving muscle force for chronic stimulation.