Neutron Scattering and Its Application to Strongly Correlated Systems

Neutron scattering is a powerful probe of strongly correlated systems. It can directly detect common phenomena such as magnetic order, and can be used to determine the coupling between magnetic moments through measurements of the spin-wave dispersions. In the absence of magnetic order, one can detect diffuse scattering and dynamic correlations. Neutrons are also sensitive to the arrangement of atoms in a solid (crystal structure) and lattice dynamics (phonons). In this chapter, we provide an introduction to neutrons and neutron sources. The neutron scattering cross section is described and formulas are given for nuclear diffraction, phonon scattering, magnetic diffraction, and magnon scattering. As an experimental example, we describe measurements of antiferromagnetic order, spin dynamics, and their evolution in the La(2-x)Ba(x)CuO(4) family of high-temperature superconductors.Comment: 31 pages, chapter for "Strongly Correlated Systems: Experimental Techniques", edited by A. Avella and F. Mancin

Comparative Analysis of Human Protein-Coding and Noncoding RNAs between Brain and 10 Mixed Cell Lines by RNA-Seq

In their expression process, different genes can generate diverse functional products, including various protein-coding or noncoding RNAs. Here, we investigated the protein-coding capacities and the expression levels of their isoforms for human known genes, the conservation and disease association of long noncoding RNAs (ncRNAs) with two transcriptome sequencing datasets from human brain tissues and 10 mixed cell lines. Comparative analysis revealed that about two-thirds of the genes expressed between brain and cell lines are the same, but less than one-third of their isoforms are identical. Besides those genes specially expressed in brain and cell lines, about 66% of genes expressed in common encoded different isoforms. Moreover, most genes dominantly expressed one isoform and some genes only generated protein-coding (or noncoding) RNAs in one sample but not in another. We found 282 human genes could encode both protein-coding and noncoding RNAs through alternative splicing in the two samples. We also identified more than 1,000 long ncRNAs, and most of those long ncRNAs contain conserved elements across either 46 vertebrates or 33 placental mammals or 10 primates. Further analysis showed that some long ncRNAs differentially expressed in human breast cancer or lung cancer, several of those differentially expressed long ncRNAs were validated by RT-PCR. In addition, those validated differentially expressed long ncRNAs were found significantly correlated with certain breast cancer or lung cancer related genes, indicating the important biological relevance between long ncRNAs and human cancers. Our findings reveal that the differences of gene expression profile between samples mainly result from the expressed gene isoforms, and highlight the importance of studying genes at the isoform level for completely illustrating the intricate transcriptome

Session 17 Ecophysiology

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Screening of Five and Six-Membered Nitrogen-Containing Heterocyclic Compounds as New Effective Stimulants of Linum Usitatissimum L. Organogenesis in Vitro

Linum usitatissimum L. (flax or linseed) is one of the oldest economically important crops used in biotechnology as a source for bioactive compounds. Flax fiber and seed have industrial significance as a source of cellulosic fiber for textile and paper industry and seed oil for pharmaceutical, cosmetic and food industry. The elaboration of new effective techniques for in vitro regeneration of Linum usitatissimum L. is very actual problem today. The influence of low molecular weight five and sixmembered nitrogen-containing heterocyclic compounds on organogenesis of Linum usitatissimum L. cultivar heavenly in vitro has been studied. It was found that heterocyclic compounds derivatives pyridine, pyrimidine, pyrazole and isoflavones revealed high stimulating effect on direct shoot organogenesis of Linum usitatissimum L. in vitro. The maximal shoot regeneration frequency was obtained on the MS media containing heterocyclic compounds at the concentration 10-8 M/l as compared to lower regeneration frequency obtained on the control MS medium containing 1 mg/l BAP and 0.05 mg/l NAA. The maximal index of explants with regeneration (in %) that exceeded almost twice the same index in control MS medium was obtained on the MS medium containing heterocyclic compound derivative of isoflavones. At the same time, the index of explants with regeneration (in %) that exceeded one and a half times the same index in control MS medium and the maximal index of shoots elongated more than 1 cm (in %) that exceeded almost twice the same index in control MS medium were obtained on the MS media containing heterocyclic compounds derivatives of pyridine, pyrimidine and pyrazole. The current study confirms perspective of using of low molecular weight five and six-membered nitrogen-containing heterocyclic compounds at the concentration 10-8 М/l of the MS medium as new effective substitutes of traditional growth regulators auxin NAA and cytokinin BAP for regeneration of Linum usitatissimum L. cultivar heavenly in vitro