2W Yb-doped double-clad fiber superfluorescent source with 42 nm 3 dB bandwidth

The output spectrum of Yb-doped double-clad fiber superfluorescent source (SFS) is tailored by placing a broadband dichroic mirror in the pump end of conventional single-pass forward configuration, which constitutes double-pass forward configuration. The 3 dB bandwidth is increased from I I to 42 nm. A maximum output SFS power of 2.12 W and a slope efficiency of 43.2% are obtained. The double-clad fiber is 25 in and the pump power is adequate to saturate the fiber as far as the feedback-induced lasing appears. (c) 2004 Elsevier Ltd. All rights reserved.

Beam conditions for radiation generated by an electromagnetic J 0-correlated Schell-model source

Based on the 2 x 2 (electric field) cross-spectral density matrix, a model for an electromagnetic J(0)-correlated Schell-model beam is given that is a generalization of the scalar J(0)-correlated Schell-model beam. The conditions that the matrix for the source to generate an electromagnetic J(0)-correlated Schell-model beam are obtained. The condition for the source to generate a scalar J(0)-correlated Schell-model beam can be considered as a special case. (C) 2008 Optical Society of America

The MLH1 c.1852_1853delinsGC (p.K618A) Variant in Colorectal Cancer: Genetic Association Study in 18,723 Individuals

Colorectal cancer is one of the most frequent neoplasms and an important cause of mortality in the developed world. Mendelian syndromes account for about 5% of the total burden of CRC, being Lynch syndrome and familial adenomatous polyposis the most common forms. Lynch syndrome tumors develop mainly as a consequence of defective DNA mismatch repair associated with germline mutations in MLH1, MSH2, MSH6 and PMS2. A significant proportion of variants identified by screening these genes correspond to missense or noncoding changes without a clear pathogenic consequence, and they are designated as "variants of uncertain significance'', being the c.1852_1853delinsGC (p.K618A) variant in the MLH1 gene a clear example. The implication of this variant as a low-penetrance risk variant for CRC was assessed in the present study by performing a case-control study within a large cohort from the COGENT consortium-COST Action BM1206 including 18,723 individuals (8,055 colorectal cancer cases and 10,668 controls) and a case-only genotype-phenotype correlation with several clinical and pathological characteristics restricted to the Epicolon cohort. Our results showed no involvement of this variant as a low-penetrance variant for colorectal cancer genetic susceptibility and no association with any clinical and pathological characteristics including family history for this neoplasm or Lynch syndrome.

Edge-defined, film-fed growth (EFG) technique for the preparation of alpha-Al2O3 : C crystal with highly sensitive thermoluminescence response

In this work, alpha-Al2O3:C, a highly sensitive thermoluminescence dosimetry crystal, was grown by the EFG method in which a graphite heating unit and shield acted as the carbon source during the growth process. The optical, luminescent properties and dosimetric characteristics of the crystal were investigated. The as-grown crystal shows a single glow peak at 536 K, which is associated with Cr3+ ions. After annealing in H-2 at 1673 K for 80 h, the crystal shows a single glow peak at 460 K and a blue emission band at 415 nm. The thermoluminescent response of the annealed crystal shows linear-sublinear-saturation characteristics in the dose range from 5 x 10(-6) to 100 Gy.

Investigating carbon materials for use as the electron emission source in a parallel electron-beam lithography system

A microelectronic parallel electron-beam lithography system using an array of field emitting microguns is currently being developed. This paper investigates the suitability of various carbon based materials for the electron source in this device, namely tetrahedrally bonded amorphous carbon (ta-C), nanoclustered carbon and carbon nanotubes. Ta-C was most easily integrated into a gated field emitter structure and various methods, such as plasma and heavy ion irradiation, were used to induce emission sites in the ta-C. However, the creation of such emission sites at desired locations appeared to be difficult/random in nature and thus the material was unsuitable for this application. In contrast, nanoclustered carbon material readily field emits with a high site density but the by-products from the deposition process create integration issues when using the material in a microelectronic gated structure. Carbon nanotubes are currently the most promising candidate for use as the emission source. We have developed a high yield and clean (amorphous carbon by-product free) PECVD process to deposit single free standing nanotubes at desired locations with exceptional uniformity in terms of nanotube height and diameter. Field emission from an array of nanotubes was also obtained. © 2001 Elsevier Science B.V.

Effect of brood source on the growth of rohu (Labeo rohita Ham.) fingerlings reared in glass tanks with formulated diets

A 60 day long feeding trial was conducted in an indoor static water system with rohu fingerlings (Labeo rohita Ham.) originating from wild brood, private and public hatcheries (denoted as A B and C respectively). They were fed on formulated diet having 34% crude protein level using indigenous ingredients. The effect of brood source on growth as well as their responses to formulated diet was observed. On the basis of the observed growth rate, food conversion ratio, protein efficiency ratio, apparent net protein utilization and apparent protein digestibility, fingerling source A showed significantly (p<0.05) higher growth, while the sources B and C produced no significantly different (p>0.05) in terms of these parameters. The results of the present study demonstrated that the fingerlings of wild source were of best quality in terms of growth and food utilization in comparison to those had the sources from hatcheries.

Cloning, characterization and expression analysis of SIMP (source of immunodominant MHC-associated peptides) in grass carp Ctenopharyngodon idella

SIMP (source of immunodominant MHC-associated peptides) plays a key rote in N-linked glycosylation with the active site of oligosaccharyltransferase, being the source of MHC-peptides in the MHC I presentation pathway. In the present study, the SIMP gene has been cloned from grass carp Ctenopharyngodon idella by rapid amplification of cDNA ends (RACE). The full length of the cDNA sequence is 4384 bp, including a 1117 bp 5' UTR (untranslated region), a 2418 bp open reading frame, and a 849 bp 3' UTR. The deduced amino acids of the grass carp SIMP (gcSIMP) are a highly conserved protein with a STT3 domain and 11 transmembrane regions. The gcSIMP spans over more than 24,212 bp in length, containing 16 exons and 15 introns. Most encoding exons, except the first and the 15th, have the same length as those in human and mouse. The gcSIMP promoter contains many putative transcription factor binding sites, such as Oct-1, GCN4, YY1, Sp1, Palpha, TBP, GATA-1, C/EBP beta, and five C/EBP alpha binding sites. The mRNA expression of gcSIMP in different organs was examined by real-time PCR. The gcSIMP was distributed in all the organs examined, with the highest level in brain, followed by the level in the heart, liver, gill, trunk kidney, muscle, head kidney, thymus, and the lowest level in spleen. Furthermore, the recombinant gcSIMP has been constructed successfully and expressed in Escherichia coli by using pQE-40 vector, and the polyclonal antibody for rabbit has been successfully obtained, which was verified to be specific. Identification of gcSIMP will help to explore the function in fish innate immunity. (c) 2007 Elsevier Ltd. All rights reserved.

Carbon source/sink function of a subtropical, eutrophic lake determined from an overall mass balance and a gas exchange and carbon burial balance

Although studies on carbon burial in lake sediments have shown that lakes are disproportionately important carbon sinks, many studies on gaseous carbon exchange across the water-air interface have demonstrated that lakes are supersaturated with CO2 and CH4 causing a net release of CO2 and CH4 to the atmosphere. In order to more accurately estimate the net carbon source/sink function of lake ecosystems, a more comprehensive carbon budget is needed, especially for gaseous carbon exchange across the water-air interface. Using two methods, overall mass balance and gas exchange and carbon burial balance, we assessed the carbon source/sink function of Lake Donghu, a subtropical, eutrophic take, from April 2003 to March 2004. With the overall mass balance calculations, total carbon input was 14 905 t, total carbon output was 4950 1, and net carbon budget was +9955 t, suggesting that Lake Donghu was a great carbon sink. For the gas exchange and carbon burial balance, gaseous carbon (CO2 and CH4) emission across the water-air interface totaled 752 t while carbon burial in the lake sediment was 9477 t. The ratio of carbon emission into the atmosphere to carbon burial into the sediment was only 0.08. This low ratio indicates that Lake Donghu is a great carbon sink. Results showed good agreement between the two methods with both showing Lake Donghu to be a great carbon sink. This results from the high primary production of Lake Donghu, substantive allochthonous carbon inputs and intensive anthropogenic activity. Gaseous carbon emission accounted for about 15% of the total carbon output, indicating that the total output would be underestimated without including gaseous carbon exchange. (C) 2007 Elsevier Ltd. All rights reserved.