1,150 research outputs found
New shield for gamma-ray spectrometry
Gamma-ray shield that can be evacuated, refilled with a clean gas, and pressurized for exclusion of airborne radioactive contaminants effectively lowers background noise. Under working conditions, repeated evacuation and filling procedures have not adversely affected the sensitivity and resolution of the crystal detector
lntrogression of Bacterial Leaf Blight Resistance Gene from Oryza Minuta J.B. Presl. Ex C. B. Presl. into New Rice Type (Oryza sativa L.)
F1 Hybrids, backcross progenies, advanced introgression lines (2n=24) and monosomic alien addition lines or MAALs (2n=25) were successfully produced following embryo rescue between an elite new plant type (NPT) breeding line of Oryza sativa (2n=24, AA) and a wild species, O. minuta (2n=48, BBCC). F1 hybrids performance were intermediate between the parents. The F1 hybrids had 36 chromosomes indicating having 12 chromosome A from O. sativa and 12 B and 12 C from O. minuta. THE BACK CROSS progenies had different chromosome number indicating abnormal meiosis of the hybrids and back cross progenies. Plant with 2n=24 and 25 chromosomes were obtained in BC4FI. The hybrids and backcross progenies were susceptible to bacterial leaf blight (BB). However, several of the 2n=24 plants derived resistant plant to bacterial leaf blight race 1 of the Philippines races. The gene is different from introgressed gene intio rice from O. longistaminata ( Xa21) and from O. Minuta Acc. 101141 I Key words: Oryza minuta, MAALS, Bacterial leaf bligh
Phylogenetic relationships among Oryza species revealed by AFLP markers
The genus Oryza to which cultivated rice belongs has 22 wild species. Seventy-seven accessions of 23 Oryza species, five related genera, and three outgroup taxa were fingerprinted using amplified fragment length polymorphism (AFLP). A total of 1191 polymorphic markers were obtained using five AFLP primer combinations. AFLP data were analyzed to study species relationships using different clustering algorithms, and the resulting phenograms were tested for stability and robustness. The findings suggest a common ancestry to the genus Oryza. Moreover, the results demonstrate that: (1) evolution in Oryza has followed a polyphyletic path wherein multiple lineages underwent independent divergence after separation early in the evolution from a common ancestor/pool of related taxa; (2) newly assigned genomes, GG for O. meyeriana and HHJJ for O. ridleyi complexes, are among the most diverged in the genus; (3) CCDD tetraploids have a relatively ancient origin among the Officinalis complex; (4) O. malampuzhaensis, O. indandamanica, O. alta, and O. grandiglumis are diverged enough to deserve species status; (5) O. officinalis and O. eichingeri (CC) are putative progenitors of O. minuta/O. malampuzhaensis and tetraploid O. punctata, respectively, (6) O. brachyantha is most diverged species in the genus. AFLP is reliable molecular technique and provides one of the most informative approaches to ascertain genetic relationships in Oryza, which may also be true for other related species/organisms
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Outcomes of elective head and neck confirmed or suspected cancer surgery during the COVID-19 pandemic.
PURPOSE: To analyse the complication outcomes of COVID-19 negative patients undergoing elective head and neck surgery during the COVID-19 pandemic. METHODS: This was a retrospective case review of all patients undergoing elective head and neck surgery for confirmed or suspected head and neck cancer. RESULTS: There were no mortalities recorded in the cohort of patients analysed. At 30 days, pulmonary complications had occurred in 4 patients (9%). None of these were related to COVID infection. CONCLUSION: With careful pre-operative screening of patients for COVID-19 and post-operative care in a COVID-19 clean ward, head and neck surgery can proceed safely during the epidemic. This data could help to minimise delay in treatment by allowing a greater number of elective head and neck cancer operations to proceed
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The helicase Ded1p controls use of near-cognate translation initiation codons in 5' UTRs.
The conserved and essential DEAD-box RNA helicase Ded1p from yeast and its mammalian orthologue DDX3 are critical for the initiation of translation1. Mutations in DDX3 are linked to tumorigenesis2-4 and intellectual disability5, and the enzyme is targeted by a range of viruses6. How Ded1p and its orthologues engage RNAs during the initiation of translation is unknown. Here we show, by integrating transcriptome-wide analyses of translation, RNA structure and Ded1p-RNA binding, that the effects of Ded1p on the initiation of translation are connected to near-cognate initiation codons in 5' untranslated regions. Ded1p associates with the translation pre-initiation complex at the mRNA entry channel and repressing the activity of Ded1p leads to the accumulation of RNA structure in 5' untranslated regions, the initiation of translation from near-cognate start codons immediately upstream of these structures and decreased protein synthesis from the corresponding main open reading frames. The data reveal a program for the regulation of translation that links Ded1p, the activation of near-cognate start codons and mRNA structure. This program has a role in meiosis, in which a marked decrease in the levels of Ded1p is accompanied by the activation of the alternative translation initiation sites that are seen when the activity of Ded1p is repressed. Our observations indicate that Ded1p affects translation initiation by controlling the use of near-cognate initiation codons that are proximal to mRNA structure in 5' untranslated regions
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