A "Schrodinger Cat" Superposition State of an Atom

A "Schrodinger cat"-like state of matter was generated at the single atom level. A trapped 9Be+ ion was laser-cooled to the zero-point energy and then prepared in a superposition of spatially separated coherent harmonic oscillator states. This state was created by application of a sequence of laser pulses, which entangles internal (electronic) and external (motional) states of the ion. The Schrodinger cat superposition was verified by detection of the quantum mechanical interference between the localized wave packets. This mesoscopic system may provide insight into the fuzzy boundary between the classical and quantum worlds by allowing controlled studies of quantum measurement and quantum decoherence.     

Molecular evolution of herbicide resistance to phytoene desaturase inhibitors in Hydrilla verticillata and its potential use to generate herbicide-resistant crops

Hydrilla [Hydrilla verticillata (Lf) Royle] is one of the most serious invasive aquatic weed problems in the USA. This plant possesses numerous mechanisms of vegetative reproduction that enable it to spread very rapidly. Management of this weed has been achieved by the systemic treatment of water bodies with the herbicide fluridone. At least three dioecious fluridone-resistant biotypes of hydrilla with two- to fivefold higher resistance to the herbicide than the wild-type have been identified. Resistance is the result of one of three independent somatic mutations at the arginine 304 codon of the gene encoding phytoene desaturase, the molecular target site of fluridone. The specific activities of the three purified phytoene desaturase variants are similar to the wild-type enzyme. The appearance of these herbicide-resistant biotypes may jeopardize the ability to control the spread of this non-indigenous species to other water bodies in the southern USA. The objective of this paper is to provide general information about the biology and physiology of this aquatic weed in relation to its recent development of resistance to the herbicide fluridone, and to discuss how this discovery might lead to a new generation of herbicide-resistant crops.     

Effect of repeated administration of combination trenbolone acetate and estradiol implants on growth, carcass traits, and beef quality of long-fed Holstein steers

Our objective was to determine the effect of repeated use of implants on feedlot performance and carcass characteristics of Holstein cattle. Holstein steers (n = 128) weighing an average of 211 kg were blocked by weight and randomly assigned to 16 pens. At the start of the trial (d 0), pens were assigned to one of four treatments: 1) nonimplanted control (C); 2) implant on d 0, 112, and 224 (T3); 3) implant on d 112 and 224 (T2); and 4) implant on d 224 (T1). Component TE-S implants (120 mg of trenbolone acetate and 24 mg of estradiol per implant) were used for all treatments during the 291-d feeding period. Over the course of the study, T2 and T3 cattle had greater ADG and final weights than C and T1 cattle (P < 0.05). Steers were harvested at a commercial abattoir on d 291. Hot carcass weights of T3 steers were greater than those of C and T1 steers (P < 0.05). Dressing percentage, adjusted 12th-rib fat, percentage of kidney, pelvic, and heart fat, yield grade, and longissimus color were not different among treatments (P > or = 0.26). Longissimus muscle areas (LMA) of T2 and T3 carcasses were larger than LMA of C (P < 0.01). No USDA Select carcasses were produced from C cattle, whereas the percentage of Select carcasses from implanted cattle ranged from 10 to 18%. Skeletal maturity advanced (P < 0.05) progressively with each additional implant. Steaks from T3 carcasses had a higher percentage of protein than controls (P < 0.05) and were less tender than all other treatments (P < 0.05). Repeated administration of combination trenbolone acetate and estradiol implants increased ADG and resulted in heavier carcasses with larger LMA. Administration of three successive implants decreased tenderness of Holstein beef, and resulted in more advanced skeletal maturity scores.     

基于3D-CDF（2,2）和3D SPIHT的序列图像压缩编码研究

研究了3D DWT和3D SPIHT算法,用CDF（2,2）双正交小波为帧内小波变换的小波基,考虑到边界延拓效应,时间维小波变换也选用CDF（2,2）双正交小波为时间维小波变换的小波基,实验结果表明算法对于视频序列图像压缩是非常有效的,其压缩效果明显优于基于3D-DCT的压缩编码算法.     

BAC-derived SSR markers chromosome locations in cotton

Bacterial artificial chromosome (BAC) libraries with large DNA fragment inserts have rapidly become the preferred choice for physical mapping. BAC-derived microsatellite or simple sequence repeats (SSRs) markers facilitate the integration of physical maps with genetic maps. The objective of this research was to identify chromosome locations of the BAC-derived SSR markers in tetraploid cotton. A total of 192 SSR primer pairs were derived from BAC clones of an Upland cotton genetic standard line TM-1 (Gossypium hirsutum L.). Metaphor agarose gel electrophoresis results revealed 76 and 59 polymorphic markers between TM-1 and 3–79 (G. barbadense) or G. tomentosum, respectively. Using deletion analysis method, we assigned 39 markers out of the 192 primer pairs to 17 different chromosomes or chromosome arms. Among them, 19 and 17 markers were localized to A-subgenomes (chromosome 1–13) and D-subgenomes (chromosome 14–26), respectively. The subgenome status for the remaining three markers remained unclear due to their two potential chromosome locations achieved by tertiary monosomic stocks deletion analysis. Chromosomal assignment of these BAC-derived SSR markers will help in integrating physical and cotton genetic linkage maps and thus facilitate positional candidate gene cloning, comparative genome analysis, and the coordination of chromosome-based genome sequencing project in cotton. Disclaimer: Mention of trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by USDA, ARS and does not imply its approval to the exclusion of other products or vendors that may also be suitable. The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Development of a Research Platform for Dissecting Phenotype–Genotype Associations in Rice (Oryza spp.)

We present an overview of a research platform that provides essential germplasm, genotypic and phenotypic data and analytical tools for dissecting phenotype–genotype associations in rice. These resources include a diversity panel of 400 Oryza sativa and 100 Oryza rufipogon accessions that have been purified by single seed descent, a custom-designed Affymetrix array consisting of 44,100 SNPs, an Illumina GoldenGate assay consisting of 1,536 SNPs, and a suite of low-resolution 384-SNP assays for the Illumina BeadXpress Reader that are designed for applications in breeding, genetics and germplasm management. Our long-term goal is to empower basic research discoveries in rice by linking sequence diversity with physiological, morphological, and agronomic variation. This research platform will also help increase breeding efficiency by providing a database of diversity information that will enable researchers to identify useful DNA polymorphisms in genes and germplasm of interest and convert that information into cost-effective tools for applied plant improvement.