Fast growing mode of stimulated Raman scattering in a pure three-wave process

Stimulated Raman scattering (SRS) of a relativistic laser in plasmas is studied in the framework of the standard equation set of a three-wave process. As far as every wave involved in the process is concerned, its evolution has two aspects: time-dependent amplitude and time-dependent frequency. These two aspects affect each other. Strict analysis and numerical experiment on the full three-wave equation set reveal that a fast growing mode of the instability, which could reach a balance or saturation point during a period far shorter than an estimation based on conventional analysis, could take place in a standard three-wave process without coupling with a fourth wave. This fast growing mode is found to stem from the constraint set by the background density on the amplitude of the driven Langmuir wave. The effect of various parameters on the development of the SRS instability is studied by numerical calculation of the history of the instability in different cases. (c) 2007 American Institute of Physics.

Low “penetrance” of phylogenetic knowledge in mitochondrial disease studies

An up-to-date view of the worldwide mitochondrial DNA (mtDNA) phylogeny together with an evaluation of the conservation of each site is a reliable tool for detecting errors in mtDNA studies and assessing the functional importance of alleged pathogenic mutations. However, most of the published studies on mitochondrial diseases make very little use of the phylogenetic knowledge that is currently available. This drawback has two inadvertent consequences: first, there is no sufficient a posteriori quality assessment of complete mtDNA sequencing efforts; and second, no feedback is provided for the general mtDNA database when apparently new mtDNA lineages are discovered. We demonstrate, by way of example, these issues by reanalysing three mtDNA sequencing attempts, two from Europe and another one from East Asia. To further validate our phylogenetic deductions, we completely sequenced two mtDNAs from healthy subjects that nearly match the mtDNAs of two patients, whose sequences gave problematic results. (c) 2005 Elsevier Inc. All rights reserved.

A possible mode of the specific recognition of nucleic acids by proteins

Seven sets of protein target sites, which occur in several gene promoters, have been analyzed. The results suggest that there is a possible mode of specific recognition of double-helical nucleic acids by proteins, This recognition mode is related to a spe

Reproduction mode of an artificial allotetraploid carp (Pisces; Cyprinidae)

Mature eggs of allotetraploid carp were activated by inactive sperm or crossed with normal sperms of common carp (Cyprinus carpio), crucian carp (Carassius auratus), Chinese blunt snout bream (Megalobrama amblycephala), Hemiculter leucisculus and Pseudorasbora parva. Chromosome counts showed that all offspring of these crosses presented a mode number of 200 chromosomes (4n = 200), and their morphological traits are much like maternal. Microsatelite marker and RAPD patterns between allotetraploid maternal and its offspring, reproduced from different paternal species, were identical. Cytological, morphological and molecular evidences suggested that allotetraploid carp female nucleus would not fuse with any male nucleus and its reproduction mode might be gynogenesis and therefore their offspring are retaining their tetraploidy and give origin to clonal individuals.

STUDY ON THE MODE OF PRIMARY CONTROL IN THE EGG OF GYNOGENETIC CRUCIAN CARP FOR INHIBITING THE DEVELOPMENT OF 2 TYPES OF SPERM NUCLEI

By comparing the different developmental characteristics of two types of sperm nuclei which were from gynogenetic fish (crucian carp) and amphimictic fishes (red carp, red goldfish and sex-reversal red carp) respectively in the eggs of gynogenetic crucian carp, it was preliminarily revealed that there existed selective inhibiting actions of the primary control in the eggs of crucian carp for inhibiting the development of the two types of sperm nuclei. To homologous sperms, the primary control showed weak effect, thus leading to the decondensation of homologous sperm nuclei at different degrees in the eggs of crucian carp. But to heterologous sperms, the primary control showed strong effects, resulting in the total inhibition of the development of heterologous sperm nuclei. Moreover, our experimental results also showed that the different developmental behavior of the two types of sperm nuclei might have a great relationship to the changes of the sex ratio in the population of gynogenetic crucian carp. The infiltration of "the genetic materials in sperm nuclei" into the female nucleus at random might play an important role in male emergence in the naturally gynogenetic population of crucian carp.

Evidence of ultrafast energy exchange-induced soft'mode of phonons and lattice instability: a nanotime effect

With a series of supportive experimental phenomena as induced by ion beam bombardment, energetic beaminduced athermal activation process in Si is demonstrated. This is correlated with phenomena induced by ultrafast energy exchange in condensed matter in general. A critical modelling is presented on the above process and a universal concept: the ultrafast energy exchange-induced soft mode of phonons and the lattice instability in condensed matter are proposed.

Distribution and mode of occurrence of As；Hg and Se and sulfur in coal Seam 3 of the Shanxi Formation,Yanzhou Coalfield；China

IEECAS SKLLQG

Separation of peptides on mixed mode of reversed-phase and ion-exchange capillary electrochromatography with a monolithic column

The mixed mode of reversed phase (RP) and strong canon-exchange (SCX) capillary electrochromatography (CEC) based on a monolithic capillary column has been developed. The capillary monolithic column was prepared by in situ copolymerization of 2-(sulfooxy)ethyl methacrylate (SEMA) and ethylene dimethacrylate (EDMA) in the presence of porogens. The sulfate group provided by the monomer SEMA on the monolithic bed is used for the generation of the electroosmotic flow (EOF) from the anode to the cathode, but at the same time serves as a SCX stationary phase. A mixed-mode (RP/SCX) mechanism for separation of peptides was observed in the monolithic column, comprising hydrophobic and electrostatic interaction as well as electrophoretic migration at a low pH value of mobile phase. A column efficiency of more than 280000 plates/m for the unretained compound has been obtained on the prepared monoliths. The relative standard deviations observed for to and retention factors of peptides were about 0.32% and less than 0.71% for ten consecutive runs, respectively. Effects of mobile phase compositions on the EOF of the monolithic column and on the separation of peptides were investigated. The selectivity on separation of peptides in the monolithic capillary column could be easily manipulated by varying the mobile phase composition.

Polymorphic EST-SSR markers and their mode of inheritance in Fenneropenaeus chinensis

229 SSRs (simple sequence repeats) were identified among 10,443 ESTs (expressed sequence tags) of Chinese shrimp (Fenneropenaeus chinensis). The average density of SSRs was one SSR per 19.1 kb of EST sequence screened. The dinucleotide repeats appeared to be the most abundant SSRs detected. Nine EST-SSR markers were detected polymorphisms of the thirty SSR primer pairs derived from F chinensis ESTs. The number of alleles per locus ranged from 5 to 15, with an average of 9.1 alleles per locus. The observed heterozygosity of nine loci ranged from 0.47 to 0.87. These loci were used successfully for pedigree analysis in three families of Fenneropenaeus chinensis. Two of the nine microsatellite loci showed the existence of null alleles. Assuming the existence of null alleles at Fc07 and Fc14 loci, the allelic inheritance mode of the EST-SSR DNA markers (Fc04, Fc06, Fc07, Fc10, Fc14, Fc18, Fc22, Fc24, and Fc27) was consistent with Mendelian segregation. (c) 2005 Elsevier B.V. All rights reserved.

Investigations of the characteristics and mode of action of an algalytic bacterium isolated from Tai Lake

An algalytic bacterium provisionally designated as TL1 was isolated from Tai Lake, a large freshwater lake in the Yangtze Delta plain on the border of the Jiangsu and Zhejiang provinces and close to Wuxi city in the People's Republic of China. Strain TL1 was identified as Achromobacter sp. based on its biophysical and biochemical properties and the analysis of its 16S rRNA sequence. Microcystis aeruginosa, which is the most common toxic cyanobacterium in eutrophic freshwater, could be decomposed by strain TL1. The results showed that after inoculation with the algalytic bacterium, the content of chlorophyll-a, maximum PSII quantum yield, and maximum electron transport rates of the alga decreased sharply. At first, the algal cells enhanced the activities of some antioxidative enzymes, but subsequently, the activities of antioxidative enzymes fell sharply once damage of the algal cells was achieved. The filtrate from strain TL1 culture suspension, after autoclaving and treatments with proteinase K, strongly inhibited algal growth, indicating that the lytic metabolites were extracellular and thermostable, not a protein.