Identification of rice landraces with promising yield and the associated genomic regions under low nitrogen

With the priority of the low input sustainable rice cultivation for environment friendly agriculture, NUE of rice becomes the need of the hour. A set of 472 rice genotypes comprising landraces and breeding lines were evaluated for two seasons under field conditions with low and recommended nitrogen and >100 landraces were identified with relative higher yield under low nitrogen. Donors were identified for higher N uptake, N translocation into grains and grain yield under low N. Grains on secondary branches, N content in grain and yield appears to be the selection criterion under low N. Through association mapping, using minimum marker set of 50 rice SSR markers, 12 genomic regions were identified for yield and yield associated traits under low nitrogen. Four associated genomic regions on chromosomes 5, 7 and 10 were fine mapped and QTL for yield under low N were identified from the marker delimited regions. Three candidate genes viz., 2-oxoglutarate /malate translocator (Os05g0208000), alanine aminotransferase (Os07g0617800) and pyridoxal phosphate-dependent transferase (Os10g0189600) from QTL regions showed enhanced expression in the genotypes with promising yield under low N. Marker assisted selection using SSR markers associated with three candidate genes identified two stable breeding lines confirmed through multi-location evaluation.

Orientational and rotational velocity correlation functions for water-hydrating B- and Z-DNA double helices

The molecular dynamics simulations reported earlier for the structure and dynamics of water molecules hydrating B- and Z-DNA double helices are analyzed for the orientational correlation functions and the proton rotational velocity autocorrelation functions. The spectra of the rotational velocity autocorrelation functions obtained from the simulation results are compared with the neutron inelastic scattering experiments on hydrated Na-DNA samples. The results predict a small frequency component associated with water molecules bound to the double helices that disappears for waters away from the double helix.

Acute otitis media in children: are decongestants or antihistamines necessary?

This study was designed to investigate the efficacy of a decongestant-antihistamine preparation in combination with antibiotic treatment of acute otitis media. The effectiveness of a new Dimetapp (DIM) preparation was assessed in comparison with each of its components (brompheniramine maleate [BPM] and phenylephrine hydrochloride [PEH] as well as a placebo (PL) vehicle in the treatment of acute otitis media. In a randomized double blind study, 98 children were treated in the emergency department or outpatient medical clinics at Children's Hospital of Michigan with amoxicillin and either DIM, BPM, PEH, or PL. They were evaluated at two weeks by clinical examination, pneumatoscopy, and tympanometry. Fifty-eight patients (59%) continued to have evidence of fluid in the middle ear. These patients were continued on the test medications for another two weeks and then reevaluated. There were significant differences between the treatment groups (DIM, BPM, and PEH) and the control PL group; the patients receiving Dimetapp or placebo fared better than those receiving BPM or PEH. However, there was no difference in the overall response between Dimetapp and placebo. Antihistamine-decongestant therapy does not appear to be necessary in the treatment of acute otitis media in children.