5,071 research outputs found

    Sunjammer

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    Familial influences on the full range of variability in attention and activity levels during adolescence: A longitudinal twin study

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    AbstractTo investigate familial influences on the full range of variability in attention and activity across adolescence, we collected maternal ratings of 339 twin pairs at ages 12, 14, and 16, and estimated the transmitted and new familial influences on attention and activity as measured by the Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder Symptoms and Normal Behavior Scale. Familial influences were substantial for both traits across adolescence: genetic influences accounted for 54%–73% (attention) and 31%–73% (activity) of the total variance, and shared environmental influences accounted for 0%–22% of the attention variance and 13%–57% of the activity variance. The longitudinal stability of individual differences in attention and activity was largely accounted for by familial influences transmitted from previous ages. Innovations over adolescence were also partially attributable to familial influences. Studying the full range of variability in attention and activity may facilitate our understanding of attention-deficit/hyperactivity disorder's etiology and intervention.</jats:p

    Study of the use of Metal-Oxide-Silicon (MOS) devices for particulate detection and monitoring in the earth's atmosphere

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    A metal-oxide-silicon (MOS) capacitor-type particulate sensor was evaluated for use in atmospheric measurements. An accelerator system was designed and tested for the purpose of providing the necessary energy to trigger the MOS-type sensor. The accelerator system and the MOS sensor were characterized as a function of particle size and velocity. Diamond particles were used as particulate sources in laboratory tests. Preliminary tests were performed in which the detector was mounted on an aircraft and flown in the vicinity of coal-fired electric generating plants

    The Inequity of Equitable Distribution: An Editorial

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    Teaching periodontal pocket charting to dental students: a comparison of computer assisted learning and traditional tutorials

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    AIM: The aim of this study was to compare the effectiveness of a computer assisted learning (CAL) programme with that of traditional small group tutorials in teaching theoretical and practical aspects of periodontal pocket charting. METHOD: Sixty-one third year undergraduate dental students were randomized to either receive a tutorial or to work through the CAL programme. Students using the CAL programme completed questionnaires relating to previous computer experience and the ease of use of the programme. All students were assessed immediately after the intervention by means of a confidence log, a practical exercise and a further confidence log. They were assessed again three weeks later by means of a confidence log and a multiple-choice written test. RESULTS: There were very few significant differences between groups for any of the assessments used. However, subjective comments indicated that students occasionally felt disadvantaged if they had not received a tutorial. CONCLUSION: CAL and traditional teaching methods are equally effective in teaching periodontal pocket charting to undergraduate dental students

    CrN-Ag self-lubricating hard coatings

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    Abstract CrN -Ag composite films, 2.5 -4 Am thick, were deposited by reactive magnetron sputtering on Si and stainless steel substrates in a 0.4 Pa pure nitrogen atmosphere at 500 -C. The layer composition was controlled by the relative power to 7.5-cm-diameter Ag and Cr targets to be 0, 3, 12, and 22 at.% Ag. The layers exhibit a dense columnar microstructure where the Ag is homogeneously distributed in the CrN matrix. The coatings were vacuum annealed for t a = 5 -60 min at temperatures ranging from T a = 600 -700 -C, to study the Ag-lubricant transport to the surface. Ag surface segregation during annealing is negligible for layers with 3 at.% Ag content. However, Ag diffuses to the surface of layers with ! 12 at.% Ag and forms particles with diameters ranging, as a function of T a and t a , from 50 to 1100 nm. Statistical analyses provide average particle sizes of 110 and 375 nm, and surface particle densities of 2 Â 10 7 and 1.7 Â 10 6 mm À 2 , for the 12 and 22% Ag samples, respectively. The Ag diffusive transport occurs 2 -3 times faster for the 22% than for the 12% sample. We attribute the increase in Ag transport as a function of the total Ag concentration to a network of pores that form during deposition due to Ag segregation into nanometer-size pockets. The pores grow in width and connectivity as the total Ag concentration is increased, leading to a faster Ag transport at elevated Ag concentrations. Room-temperature micro-scratch tests show that the average friction coefficients and wear track depths monotonically decrease, by 27 and 56%, respectively, when the Ag concentration is increased from 0 to 22 at.%

    Li non-stoichiometry and crystal growth of untwinned 1D quantum spin system Lix Cu2 O2

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    Floating-zone growth of untwinned single crystal of Li_xCu_2O_2 with high Li content of x ~ 0.99 is reported. Li content of Li_xCu_2O_2 has been determined accurately through combined iodometric titration and thermogravimetric methods, which also ruled out the speculation of chemical disorder between Li and Cu ions. The morphology and physical properties of single crystals obtained from slowing-cooling (SL) and floating-zone (FZ) methods are compared. The floating-zone growth under Ar/O_2=7:1 gas mixture at 0.64 MPa produces large area of untwinned crystal with highest Li content, which has the lowest helimagnetic ordering temperature ~19K in the Li_xCu_2O_2 system.Comment: 4 pages, 3 figure

    Privacy Architectures: Reasoning About Data Minimisation and Integrity

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    Privacy by design will become a legal obligation in the European Community if the Data Protection Regulation eventually gets adopted. However, taking into account privacy requirements in the design of a system is a challenging task. We propose an approach based on the specification of privacy architectures and focus on a key aspect of privacy, data minimisation, and its tension with integrity requirements. We illustrate our formal framework through a smart metering case study.Comment: appears in STM - 10th International Workshop on Security and Trust Management 8743 (2014

    The Art and Science of Immunosuppression: The Fifth Annual American Society of Transplant Surgeon's State-of-the-Art Winter Symposium

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72057/1/j.1600-6143.2005.01187.x.pd

    The use of antibodies to the polypyrimidine tract binding protein (PTB) to analyze the protein components that assemble on alternatively spliced pre-mRNAs that use distant branch points

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    We are using the rat beta-tropomyosin (beta-TM) gene as a model system to study the mechanism of alternative splicing. Previous studies demonstrated that the use of the muscle-specific exon is associated with the use of distant branch points located 147-153 nt upstream of the 3' splice site. In addition, at least one protein, the polypyrimidine tract binding protein (PTB), specifically interacts with critical cis-acting sequences upstream of exon 7 that are involved in blocking the use of this alternative exon in nonmuscle cells. In order to further study the role of PTB, monoclonal antibodies to PTB were prepared. Anti-PTB antibodies did not inhibit the binding of PTB to RNA because they were able to supershift RNA-PTB complexes. To determine if additional proteins interact with sequences within the pre-mRNA, 35S-met-labeled nuclear extracts from HeLa cells were mixed with RNAs and the RNA-protein complexes were recovered by immunoprecipitation using antibodies to PTB. When RNAs containing intron 6 were added to an 35S-met-labeled nuclear extract, precipitation with PTB antibodies showed a novel set of proteins. By contrast, addition of RNAs containing introns 5 or 7 gave the same results as no RNA, indicating that these RNAs are unable to form stable complexes with PTB. These results are in agreement with our previous studies demonstrating that PTB interacts with sequences within intron 6, but not with sequences within introns 5 and 7. When 35S-met-labeled HeLa nuclear extracts were mixed with biotinylated RNA containing intron 6 and the RNA-protein complexes were recovered using streptavidin-agarose beads, an identical pattern of proteins was observed when compared with the immunoprecipitation assay. Analysis of the proteins that assembled on introns 5, 6, or 7 using biotinylated RNA revealed a unique set of proteins that interact with each of these sequences. The composition of proteins interacting with sequences associated with the use of the 3' splice site of intron 6 included proteins of 30, 40, 55, 60, 65, 70, 80, and 100 kDa. Microsequencing identified two of the proteins to be Sam68 and the Far Upstream Element Binding Protein (FBP) from the c-myc gene. In addition, a comparison of the proteins that assemble on introns from the alpha- and beta-TM genes that utilize distant branch points revealed common as well as unique proteins that assemble on these introns. These studies identify a set of proteins, in addition to PTB, that are likely involved in the use of distant branch sites associated with the use of alternatively spliced introns
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