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Although both human epidemiologic and animal model studies have suggested that caffeine/coffee protects against Alzheimer's disease, direct human evidence for this premise has been lacking. In the present case-control study, two separate cohorts consisting of 124 total individuals (65-88 years old) were cognitively assessed and a blood sample taken for caffeine/biomarker analysis. Subjects were then monitored for cognitive status over the ensuing 2-4 year period to determine the extent to which initial plasma caffeine/biomarkers levels would be predictive of changes in cognitive status. Plasma caffeine levels at study onset were substantially lower (-51%) in mild cognitive impairment (MCI) subjects who later progressed to dementia (MCI→DEM) compared to levels in stable MCI subjects (MCI→MCI). Moreover, none of the MCI→DEM subjects had initial blood caffeine levels that were above a critical level of 1200 ng/ml, while half of stable MCI→MCI subjects had blood caffeine levels higher than that critical level. Thus, plasma caffeine levels greater than 1200 ng/ml (≈6 μM) in MCI subjects were associated with no conversion to dementia during the ensuing 2-4 year follow-up period. Among the 11 cytokines measured in plasma, three of them (GCSF, IL-10, and IL-6) were decreased in MCI→DEM subjects, but not in stable MCI→MCI subjects with high plasma caffeine levels. Coffee would appear to be the major or perhaps only source of caffeine for such stable MCI patients. This case-control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset, particularly for those who already have MCI. [ABSTRACT FROM AUTHOR]

Abstract: The thickness dependent crystallization behavior of thin amorphous Ge2Sb2Te5(GST) films sandwiched between different cladding materials has been investigated based on a thermodynamic model. It is revealed that there is a critical thickness below which the crystallization cannot occur. The critical thickness is determined by the energy difference Δγ between the crystalline GST/substrate interface energy and the amorphous GST/substrate interface energy, the melting enthalpy, and the mole volume. The calculated result is in good agreement with the experiments. Furthermore, the crystallization temperature is also affected by interface energy difference Δγ. Larger Δγ gives rise to a higher crystallization temperature, and vice versa. This impact becomes stronger as the film thickness is decreased. [Copyright &y& Elsevier]

Objective: To explore the role of mother's peripheral blood mononuclear cell (PBMC) infected with hepatitis B virus (HBV) in intrauterine transmission. Methods: We have selected 60 cases of pregnant women with negative serum HBV DNA and positive PBMC HBV DNA from hospitalized patients. These women and their neonates acted as the experimental group. Twenty cases of pregnant women with HBV serum marker negative were selected. These women and their neonates served as the control group. Immunohistochemistry was employed to detect the expressions of HBsAg and HBcAg in cells of every placental layer and CD68 cells of placenta of the pregnant women whose neonates' PBMC HBV DNA was positive and/or whose neonates' serum HBV DNA positive. Results: In the experimental group, neonatal serum HBV DNA of only four cases were positive, only eight cases' neonatal PBMC HBV DNA were positive and four cases had HBV DNA positive in both neonatal serum and PBMC. The expressions of HBsAg and HBcAg were detected in CD68 cells of villous stroma and blood capillary in only eight cases of neonatal placenta with positive PBMC HBV DNA. HBV infection was found in cells of every layer in placenta in two of four cases with neonatal serum HBV DNA positive. The expressions of HBsAg and HBcAg were detected in trophoblastic cells, CD68 cells of villous stroma and blood capillary in two of four cases with HBV DNA positive in both neonatal serum and PBMC. In control group, no positive signals were detected in neonates and placenta. Conclusion: HBV-infected PBMC in pregnant women may lead to intrauterine infection. [ABSTRACT FROM AUTHOR]

Information on droplet dynamics and evaporation from sprinklers is important for the design of irrigation systems. To obtain improved predictions, a modified mathematical model of droplet ballistics and evaporation for sprinkler irrigation was developed. Air drag force is an important factor affecting the droplet dynamics and evaporation. Five different schemes for calculating the air drag coefficient of droplet were compared and the optimal one was selected. From sensitivity analyses, it was concluded that droplet evaporation rate was most sensitive to droplet diameter for droplets<2mm, and to relative humidity for droplets>2mm. The calculation scheme used by Park et al. {Transactions of the ASAE, 25(2), 357–361 (1982) and (3), 795–804, (1983)} was selected since it provided the best prediction of droplet flight distance. The model was verified using experimental results from droplet fall velocities and loss rates. The average relative error between the predicted and measured data of fall velocities and loss rates were 1.2% and 4.3%, respectively. The average relative error of the total evaporation rate between the predicted and measured data was 17.5%. [Copyright &y& Elsevier]

A major quantitative trait locus (QTL) associated with resistance to Fusarium head blight (FHB) was identified on chromosome 3BS between simple sequence repeat (SSR) markers Xgwm389 and Xgwm493 in wheat “Ning 7840”, a derivative from “Sumai 3”. However, the marker density of SSR in the QTL region was much lower than that required for marker-assisted selection (MAS) and map-based cloning. The objective of this study was to exploit new markers to increase marker density in this QTL region by using single-strand conformational polymorphism (SSCP) markers developed from wheat-expressed sequence tags (ESTs) on 3BS bin 8-0.78-1.0. Sixty-nine out of 85 SSCP primer pairs amplified PCR (polymerase chain reaction) products from the genomic DNA of “Chinese Spring”. Thirty-four primer pairs amplified PCR products that could form clear ssDNA (single strand DNA) bands through denaturation treatment. Ten SSCP markers had polymorphisms between Ning 7840 and “Clark”. Five of the ten polymorphic SSCP markers were located on chromosome 3B by nullitetrasomic analysis. Three SSCP markers ( Xsscp6, Xsscp20, and Xsscp21) were mapped into the region between Xgwm493 and Xgwm533 and possessed a higher coefficient of determination (R2) than Xgwm493 and Xgwm533. The SSCP markers, Xsscp6, Xsscp20, and Xsscp21, can be used for map-based cloning of the QTL and for marker-assisted selection in FHB resistance breeding. [ABSTRACT FROM AUTHOR]

Use of diverse sources of Fusarium head blight (FHB)-resistant germ-plasm in breeding may significantly improve wheat resistance to FHB. Wangshuibai is an FHB-resistant Chinese landrace unrelated to cv. Sumai 3, the most commonly used FHB-resistant source. In all, 139 F6 recombinant inbred lines were developed from a cross between Wangshuibai and an FHB-susceptible cultivar. Wheaton, to map quantitative trait loci (QTL) for wheat resistance to initial infection (type I resistance), spread of FHB symptoms within a spike (type II resistance), and deoxynivalenol (DON) accumulation (type III resistance) in infected grain. The experiments were conducted in a greenhouse at Manhattan, KS from 2003 to 2005. More than 1,300 simple-sequence repeat and amplified fragment length polymorphism markers were analyzed in this population. Five QTL for type I resistance were detected on chromosomes 3AS, 3BS, 4B, 5AS, and 5DL after spray inoculation: seven QTL for type II resistance were identified on chromosomes 1A, 3BS+ 3DL+ 5AS, 5DL, and 7AL after point inoculation: and seven QTL for type III resistance were detected on chromosomes 1A, 1BL, 3BS, 5AS, 5DL, and 7AL with the data from both inoculation methods. These QTL jointly explained up to 31.7, 64, and 52.8% of the phenotypic variation for the three types of FHB resistance, respectively. The narrow-sense heritabilifies were low for type I resistance (0.37 to 0.41) but moderately high for type II resistance (0.45 to 0.61 ) and type Ill resistance (0.44 to 0.67). The QTL on the distal end of 3BS, 5AS, and 5DL contributed to all three types of resistance. Two QTL, on 7AL and IA, as well as one QTL near the centromere of 3BS (3BSch showed effects on both type II and type III resistance. Selection for type II resistance mlandraceay simultaneously improve type I and type III resistance as well. The QTL for FHB resistance identified in Wangshuibai have potential to be used to pyramid FHB-resistance QTL from different sources. [ABSTRACT FROM AUTHOR]

New coherent radiation sources in the hard X-ray and Terahertz regimes promise exciting new developments in science, as previously dark areas of the spectrum are brightly illuminated. Ultra-short, ultra-bright radiation packets can probe the structure of matter, and image chemical and biological processes well beyond the present state of the art. Production of this coherent radiation, however, places an unprecedented challenge on the production and acceleration of high-quality electron beams. To deliver a nano-Coulomb of charge with an emittance of less than one micron, while transporting the beam through long sections of acceleration and compression, is the prerequisite for unlocking the gates of this promising new science. Using a low-energy electron storage ring, we deliberately enhance the space charge force while slowing down the time-scale to easily measurable levels so as to maximize our understanding of the particle dynamics necessary for producing bright beams. [ABSTRACT FROM AUTHOR]

Abstract: The University of Maryland Electron Ring (UMER) and the Long Solenoid Experiment (LSE) are two electron machines that were designed explicitly to study the physics of space-charge-dominated beams. The operating parameters of these machines can be varied by choice of apertures and gun operating conditions to access a wide range of parameters that reproduce, on a scaled basis, the full nonlinear time-dependent physics that is expected in much costlier ion systems. Early operation of these machines has demonstrated the importance of the details of beam initial conditions in determining the downstream evolution. These machines have also been a convenient tested for benchmarking simulation codes such as WARP, and for development of several novel diagnostic techniques. We present our recent experience with multi-turn operation as well as recent longitudinal and transverse physics experiments and comparisons to simulation results. Development of novel diagnostic techniques such as time-dependent imaging using optical transition radiation and tomographic beam reconstruction are also described. [Copyright &y& Elsevier]

Abstract: Magnetic powders for sintered NdFeB magnets have been prepared by using an advanced processing method including strip casting, hydrogen decrepitation, jet milling and rubber isotropic press. The effects of Dy, Ga and Co addition on the microstructure and magnetic properties of sintered magnets have been investigated. By adopting a suitable component ratio and adjusting proper technological parameters, we have prepared high-coercivity sintered NdFeB magnets with hard magnetic properties of j H c=25.6kOe, B r=13.2kG and (BH)max=39.9MGOe. The temperature coefficient of coercivity of the magnets (between 20 and 150°C) is –0.53%/°C. The magnetic properties at high temperature satisfy the needs of permanent magnet motors. [Copyright &y& Elsevier]

Wangshuibai is a Chinese landrace wheat with a high level of resistance to fusarium head blight (FHB) and deoxynivalenol (DON) accumulation. Using an F7 population of recombinant inbred lines (RILs) derived from the cross between Wangshuibai and Annong 8455 for molecular mapping of quantitative trait loci (QTL) for FHB resistance, the proportion of scabbed spikelets (PSS) and DON content were assessed under field conditions. Composite interval mapping revealed that two and three QTL were significantly associated with low PSS and low DON content, respectively, over 2 years. QTL on chromosomes 3B and 2A explained 17 and 11·5%, respectively, of the phenotypic variance for low PSS, whereas QTL on chromosomes 5A, 2A and 3B explained 12·4, 8·5 and 6·2%, respectively, of the phenotypic variance for low DON content. The 3B QTL appeared to be associated mainly with low PSS, and the 5A QTL primarily with low DON content in Wangshuibai. The 2A QTL had minor effects on both low PSS and DON content. Microsatellite and AFLP markers linked to these QTL should be useful for marker-assisted selection of QTL for low PSS and low DNA content from Wangshuibai. [ABSTRACT FROM AUTHOR]

Aging aerospace structures undergo severe damage due to corrosion, fatigue, creep, and other factors. The objective of this study is to estimate a unique parameter, called a safety index that gives an indication of the safety or reliability of these structures. To obtain the safety index, evolutionary computations using neural network based particle swarm optimization technique were developed to evolve the required data for the network. A simulation program, based on the neural network and optimization techniques, was implemented in MS visual basic/VC++ environment to predict the safety index of a damaged structure. Analytical solutions were used to predict the effects of crack, fatigue, and creep damage mechanisms. The results obtained from the simulation program were compared to the analytical solutions as there is no experimental data available for multiple damage mechanisms of an aging structure. Based on the results obtained, it appears that the proposed approach of obtaining the safety of a structure is reasonable, and the developed simulation program might be useful as an initial estimate to assess the structural integrity. However, more experimental work will be needed to establish the utility of this approach for practical applications. [ABSTRACT FROM AUTHOR]

Outbreaks of highly pathogenic avian influenza (HPAI) have been occurring in domestic poultry in Asia since 1996. In the beginning of 2004, HPAI outbreaks were caused by H5N1 virus in two farms and a group of pet chickens in different areas of Japan. In the present study, the pathogenicity of A/chicken/Yamaguchi/7/04 (H5N1), which had been isolated from a dead chicken during the first outbreak in Japan, was assessed in chickens, quails, budgerigars, ducklings, mice, and miniature pigs by experimental infection. The virus was highly pathogenic to all the birds tested. Mice were susceptible to infection with a low mortality rate and miniature pigs were resistant to infection with the virus. [ABSTRACT FROM AUTHOR]

Abstract: Some of the most challenging and interesting problems in nature involve large numbers of objects or particles mutually interacting through long-range forces. Examples range from galaxies and plasmas to flocks of birds and traffic flow on a highway. Even in cases where the form of the interacting force is precisely known, such as the 1/r 2-dependent Coulomb and gravitational forces, such problems present a formidable theoretical and modeling challenge for large numbers of interacting bodies. This paper reports on a newly constructed, scaled particle accelerator that will serve as an experimental testbed for the dynamics of swarms interacting through long-range forces. Primarily designed for intense beam dynamics studies for advanced accelerators, the University of Maryland Electron Ring (UMER) design is described in detail and an update on commissioning is provided. An example application to a system other than a charged particle beam is discussed. [Copyright &y& Elsevier]

Chinese Spring Sumai 3 chromosome 7A disomic substitution line (CS-SM3-7ADS) is highly resistant to Fusarium head blight (FHB), and an F7 population of recombinant inbred lines derived from the cross CS-SM3-7ADS x Annong 8455 was evaluated for resistance to FHB to investigate main effects, epistasis, and environmental interactions of quantitative trait loci (QTLs) for FHB resistance. A molecular linkage map consists of 501 simple sequence repeat and amplified fragment length polymorphism markers. A total of 10 QTLs were identified with significant main effects on the FHB resistance using MapQTL and QTLMapper software. Among them, CS-SM3-7ADS carries FHB-resistance alleles at five QTLs on chromosomes 2D, 3B, 4D, and 6A. One QTL on 3BS had the largest effect and explained 30.2% of the phenotypic variance. Susceptible QTLs were detected on chromosomes 1A, 1D, 4A, and 4B. A QTL for enhanced FHB resistance was not detected on chromosome 7A of CS-SM3-7ADS; therefore, the increased FHB resistance in CS-SM3-7ADS was not due to any major FHB-resistance QTL on 7A of Sumai 3, but more likely was due to removal of susceptible alleles of QTLs on 7A of Chinese Spring. QTLMapper detected nine pairs of additive-additive interactions at 17 loci that explained 26% phenotypic variance. QTL-environment interactions explained 49% of phenotypic variation, indicating that the environments significantly affected the expression of the QTLs, especially these epistasis QTLs. Adding FHB-enhancing QTLs or removal of susceptible QTLs both may significantly enhance the degree of wheat resistance to FHB in a wheat cultivar. [ABSTRACT FROM AUTHOR]

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is an important foliar disease of wheat worldwide. Pyramiding race-specific genes into a single cultivar and combining race-specific resistance genes with durable resistance genes are the preferred strategies to improve the durability of powdery mildew resistance. The objectives of this study were to characterize a powdery mildew resistance gene in Suwon 92 and identify gene-specific or tightly linked molecular markers for marker-assisted selection (MAS). A population of recombinant inbred lines (RILs) was derived by single seed descent from a cross between Suwon 92 and a susceptible cultivar, CI 13227. The RILs were screened for adult-plant infection type of powdery mildew and characterized with amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. The linked markers explained 41.3 to 69.2% of the phenotypic variances measured in 2 years. A morphological marker, hairy glume, was also associated with powdery mildew resistance in Suwon 92, and explained 43 to 51% of the phenotypic variance. The powdery mildew resistance gene in Suwon 92 was located on the short arm of chromosome 1A where Pm3 was located. Two gene-specific markers were developed based on the sequence of the cloned Pm3b gene. These two markers, which were mapped at the same locus in the peak region of the LOD score for the RIL population, explained most of the phenotypic variance for powdery mildew resistance in the RIL population. The powdery mildew resistance in Suwon 92 is most likely conditioned by the Pm3 locus. The gene markers developed herein can be directly used for MAS of some of the Pm3 alleles in breeding programs. [ABSTRACT FROM AUTHOR]

The University of Maryland Electron Ring (UMER) is a low-energy, high current recirculator for beam physics research [M. Reiser et al., in Proceedings of the 1999 Particle Accelerator Conference, New York, NY (IEEE, New York, 1999), p. 234]. Ring construction is completed for multiturn operation of beams over a broad range of intensities and initial conditions. UMER is an extremely versatile experimental platform with a beam current of up to 100 mA and a pulse length as long as 100 ns. UMER is addressing issues in beam physics relevant to many applications that require intense beams of high quality, such as advanced concept accelerators, free electron lasers, spallation neutron sources, and future heavy-ion drivers for inertial fusion. The primary focus of this paper is to present experimental results in the areas of beam steering and multiturn operation of the ring. Unique beam steering algorithms now include measurement of the beam response matrix at each quadrupole and matrix inversion by singular value decomposition. With these advanced steering methods, transport of an intense beam over four turns (144 full lattice periods) of the ring has been achieved. [ABSTRACT FROM AUTHOR]

Assesses the emergence of extensively-drug resistant (XDR) tuberculosis (TB) worldwide during 2000-2004. Number of XDR TB reported during the period; Implication of the emergence of XDR TB for public health; Result of the survey conducted by the U.S. Centers for Disease Control and Prevention and the World Health Organization (WHO) on the WHO/International Union Against Tuberculosis and Lung Disease Global Supranational TB Reference Laboratory Network.

Bermudagrass [Cynodon dactylon (L.) Pers.] is widely distributed in China, but little information exists on genetic diversity within the germplasm pool. This study was conducted to assess variations in ploidy and amplified fragment length polymorphisms (AFLPs) among Cynodon accessions collected from 11 Chinese provinces. Flow cytometry and AFLP analyses were performed on 132 and 119 Chinese accessions, respectively. Four ploidy cytotypes were found among the Chinese accessions. Tetraploid (2n = 4x = 36) accessions were most prevalent (88%), with nuclear genome sizes ranging from 1.96 to 2.30 pg/2C nucleus-1. Seven hexaploid (2n = 6x = 54), three pentaploid (2n = 5x = 45), and six triploid (2n = 3x = 27) accessions had respective nuclear genome size of 2.90 to 3.13, 2.37 to 2.49, and 1.55 to 1.65 pg/2C nucleus-1. The accessions were grouped into five clusters based on 466 polymorphic AFLP bands. Genetic similarity coefficients (GSCs) of two clusters containing ‘Tifway’ and ‘Tifgreen’ ranged from 0.97 to 0.99, suggesting the triploid plants most probably were introduced cultivars from the USA. Within the Chinese indigenous accessions, GSC ranged from 0.65 to 0.99. Tetraploid genotypes had the greatest genetic variation with GSC ranging from 0.69 to 0.99, while pentaploids had the least with GSC ranging from 0.95 to 0.98. Genetic differentiation among the later three ploidy levels is evident. Fully sampling the genetic diversity of Cynodon in China will require more comprehensive collection throughout its distribution. [ABSTRACT FROM AUTHOR]

Grain yield and associated agronomic traits are important factors in wheat ( Triticum aestivum L.) improvement. Knowledge regarding the number, genomic location, and effect of quantitative trait loci (QTL) would facilitate marker-assisted selection and the development of cultivars with desirable characteristics. Our objectives were to identify QTLs directly and indirectly affecting grain yield expression. A population of 132 F12 recombinant inbred lines (RILs) was derived by single-seed descent from a cross between the Chinese facultative wheat Ning7840 and the US soft red winter wheat Clark. Phenotypic data were collected for 15 yield and other agronomic traits in the RILs and parental lines from three locations in Oklahoma from 2001 to 2003. Twenty-nine linkage groups, consisting of 363 AFLP and 47 SSR markers, were identified. Using composite interval mapping (CIM) analysis, 10, 16, 30, and 14 QTLs were detected for yield, yield components, plant adaptation (shattering and lodging resistance, heading date, and plant height), and spike morphology traits, respectively. The QTL effects ranged from 7 to 23%. Marker alleles from Clark were associated with a positive effect for the majority of QTLs for yield and yield components, but gene dispersion was the rule rather than the exception for this RIL population. Often, QTLs were detected in proximal positions for different traits. Consistent, co-localized QTLs were identified in linkage groups 1AL, 1B, 4B, 5A, 6A, and 7A, and less consistent but unique QTLs were identified on 2BL, 2BS, 2DL, and 6B. Results of this study provide a benchmark for future efforts on QTL identification for yield traits. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The purpose of this study was to investigate the presence and distribution of Hepatitis B virus antigen (HBVAg) and Hepatitis B virus deoxyribonucleic acid (HBVDNA) in ovary with chronic hepatitis B virus. STUDY DESIGN: The immunohistochemistry method and in situ hybridization method were used to detect the hepatitis B surface antigen (HBsAg), anti-hepatitis B core antibody (HBcAg), and HBVDNA in ovary of patients with chronic hepatitis B infection. RESULTS: HBsAg presented in the ovum-granular cell and interstitial cell of ovary. HBsAg located in the cytomembrane and cytoplasm. HBcAg presented in the ovum-granular cell-interstitial cell and endothelium cell of interstitial blood vessel of ovary, and the HBcAg may present in the ovum at different stage. HBcAg was situated at the cytomembrane, cytoplasm, and nucleus. HBVDNA was detected in the ovum at different stage as HBcAg and in granular cell, interstitial cell of ovary. In the same ovary tissue, HBVDNA was positive in some ova, but it was weakly positive or negative in other ova. HBVDNA distributed mainly in nucleus, but also can be detected in the cytoplasm. CONCLUSION: HBV could infect the ovum at different stage and replicate in it. This may be an important mechanism of HBV vertical transmission. [ABSTRACT FROM AUTHOR]