7,760 research outputs found
The Southern 2MASS AGN Survey: spectroscopic follow-up with 6dF
The Two Micron All-Sky Survey (2MASS) has provided a uniform photometric
catalog to search for previously unknown red AGN and QSOs. We have extended the
search to the southern equatorial sky by obtaining spectra for 1182 AGN
candidates using the 6dF multifibre spectrograph on the UK Schmidt Telescope.
These were scheduled as auxiliary targets for the 6dF Galaxy Redshift Survey.
The candidates were selected using a single color cut of J - Ks > 2 to Ks ~
15.5 and a galactic latitude of |b|>30 deg. 432 spectra were of sufficient
quality to enable a reliable classification. 116 sources (or ~27%) were
securely classified as type 1 AGN, 20 as probable type 1s, and 57 as probable
type 2 AGN. Most of them span the redshift range 0.05<z<0.5 and only 8 (or ~6%)
were previously identified as AGN or QSOs. Our selection leads to a
significantly higher AGN identification rate amongst local galaxies (>20%) than
in any previous galaxy survey. A small fraction of the type 1 AGN could have
their optical colors reddened by optically thin dust with A_V<2 mag relative to
optically selected QSOs. A handful show evidence for excess far-IR emission.
The equivalent width (EW) and color distributions of the type 1 and 2 AGN are
consistent with AGN unified models. In particular, the EW of the [OIII]
emission line weakly correlates with optical--near-IR color in each class of
AGN, suggesting anisotropic obscuration of the AGN continuum. Overall, the
optical properties of the 2MASS red AGN are not dramatically different from
those of optically-selected QSOs. Our near-IR selection appears to detect the
most near-IR luminous QSOs in the local universe to z~0.6 and provides
incentive to extend the search to deeper near-IR surveys.Comment: 57 pages, 12 figures, 4 tables, to appear in vol.27/4 of Publications
of the Astronomical Society of Australia (PASA
Unexpected Nickel Complex Speciation Unlocks Alternative Pathways for the Reactions of Alkyl Halides with dppf-Nickel(0)
The mechanism of the reactions between dppf-Ni0 complexes and alkyl halides has been investigated using kinetic and mechanistic experiments and DFT calculations. The active species is [Ni(κ2-dppf)(κ1-dppf)], which undergoes a halide abstraction reaction with alkyl halides and rapidly captures the alkyl radical that is formed. The rates of the reactions of [Ni(COD)(dppf)] with alkyl halides and the yields of prototypical nickel-catalyzed Kumada cross-coupling reactions of alkyl halides are shown to be significantly improved by the addition of free dppf ligand
Lily Day, Wednesday, March 4, 1964
Comments on past research in Ohio on Lilies / D. C. Kiplinger -- Lily investigations / Abdel-Alim M. Shoushan -- Further studies on causes and control of leaf scorch in Croft Easter lily / N. W. Stuart, William Skou, and D. C. Kiplinger -- Fertilizer and lime affect amount of leaf scorch in Croft Easter lilies / Neil W. Stuart, K. S. Nelson and D. C. Kiplinger -- Comparative development of Ace and Nellie White lilies / Dennis Rider and D. C. Kiplinger -- Experiments with potted lilies, 1961-1962 / D. C. Kiplinger, Robert O. Miller, Howard Jones, and Dennis Rider -- Lily culture and timing for Easter, 1964 / D. C. Kiplinger and Robert O. Miller -- High temperature treatment of Easter lily bulbs / Robert O. Miller and D. C. Kiplinger -- An investigation of causes of variation in the growth of commercial and experimental lilies / Robert O. Miller and D. C. Kiplinger -- Applying terraclor with or without dexon / D. C. Kiplinger, Robert O. Miller and Leonard J. Her
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Exploration of methods to identify polymorphisms associated with variation in DNA repair capacity phenotypes
Elucidating the relationship between polymorphic sequences and risk of common disease is a challenge. For example, although it is clear that variation in DNA repair genes is associated with familial cancer, aging and neurological disease, progress toward identifying polymorphisms associated with elevated risk of sporadic disease has been slow. This is partly due to the complexity of the genetic variation, the existence of large numbers of mostly low frequency variants and the contribution of many genes to variation in susceptibility. There has been limited development of methods to find associations between genotypes having many polymorphisms and pathway function or health outcome. We have explored several statistical methods for identifying polymorphisms associated with variation in DNA repair phenotypes. The model system used was 80 cell lines that had been resequenced to identify variation; 191 single nucleotide substitution polymorphisms (SNPs) are included, of which 172 are in 31 base excision repair pathway genes, 19 in 5 anti-oxidation genes, and DNA repair phenotypes based on single strand breaks measured by the alkaline Comet assay. Univariate analyses were of limited value in identifying SNPs associated with phenotype variation. Of the multivariable model selection methods tested: the easiest that provided reduced error of prediction of phenotype was simple counting of the variant alleles predicted to encode proteins with reduced activity, which led to a genotype including 52 SNPs; the best and most parsimonious model was achieved using a two-step analysis without regard to potential functional relevance: first SNPs were ranked by importance determined by Random Forests Regression (RFR), followed by cross-validation in a second round of RFR modeling that included ever more SNPs in declining order of importance. With this approach 6 SNPs were found to minimize prediction error. The results should encourage research into utilization of multivariate analytical methods for epidemiological studies of the association of genetic variation in complex genotypes with risk of common diseases
Identification and characterization of an inhibitory fibroblast growth factor receptor 2 (FGFR2) molecule, up-regulated in an Apert Syndrome mouse model
AS (Apert syndrome) is a congenital disease composed of skeletal, visceral and neural abnormalities, caused by dominant-acting mutations in FGFR2 [FGF (fibroblast growth factor) receptor 2]. Multiple FGFR2 splice variants are generated through alternative splicing, including PTC (premature termination codon)-containing transcripts that are normally eliminated via the NMD (nonsense-mediated decay) pathway. We have discovered that a soluble truncated FGFR2 molecule encoded by a PTC-containing transcript is up-regulated and persists in tissues of an AS mouse model. We have termed this IIIa–TM as it arises from aberrant splicing of FGFR2 exon 7 (IIIa) into exon 10 [TM (transmembrane domain)]. IIIa–TM is glycosylated and can modulate the binding of FGF1 to FGFR2 molecules in BIAcore-binding assays. We also show that IIIa–TM can negatively regulate FGF signalling in vitro and in vivo. AS phenotypes are thought to result from gain-of-FGFR2 signalling, but our findings suggest that IIIa–TM can contribute to these through a loss-of-FGFR2 function mechanism. Moreover, our findings raise the interesting possibility that FGFR2 signalling may be a regulator of the NMD pathway
Measuring news bias: Russia’s official news agency ITAR-TASS’ coverage of the Ukraine crisis
Objectivity in news reporting is one of the most widely discussed topics in journalism, and a number of studies on bias in news have been conducted, but there is little agreement on how to define or measure news bias. Aiming to settle the theoretical and methodological disagreement, the author redefined news bias and applied a new methodology to detect the Russian government’s influence on ITAR-TASS during the Ukraine crisis. A longitudinal content analysis of over 35,000 English-language newswires on the Ukraine crisis published by ITAR-TASS and Interfax clearly showed that ITAR-TASS’ framing of Ukraine was reflecting desirability of pivotal events in the crisis to the Russian government. This result reveals Russia’s strategic use of the state-owned news agency for international propaganda in its ‘hybrid war’, demonstrating the effectiveness of the new approach to news bias
Measures of Parent-Infant Interaction
Increasingly, programs for handicapped infants and toddlers are including in their intervention activities objectives related to the quality of parent-child interaction. As a consequence, it has become necessary for programs to assess the impact of these intervention efforts on parent behaviors. This article considers tools available for assessing parent-child interaction for program planning and evaluation. Lastly, recommendations are offered to guide the selection of a measure of parent-child interactions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69100/2/10.1177_027112148600600204.pd
Finite Theories and the SUSY Flavor Problem
We study a finite SU(5) grand unified model based on the non-Abelian discrete
symmetry A_4. This model leads to the democratic structure of the mass matrices
for the quarks and leptons. In the soft supersymmetry breaking sector, the
scalar trilinear couplings are aligned and the soft scalar masses are
degenerate, thus solving the SUSY flavor problem.Comment: 17 pages, LaTeX, 1 figur
Rationale and design of the Exercise Intensity Trial (EXCITE): A randomized trial comparing the effects of moderate versus moderate to high-intensity aerobic training in women with operable breast cancer
<p>Abstract</p> <p>Background</p> <p>The Exercise Intensity Trial (EXcITe) is a randomized trial to compare the efficacy of supervised moderate-intensity aerobic training to moderate to high-intensity aerobic training, relative to attention control, on aerobic capacity, physiologic mechanisms, patient-reported outcomes, and biomarkers in women with operable breast cancer following the completion of definitive adjuvant therapy.</p> <p>Methods/Design</p> <p>Using a single-center, randomized design, 174 postmenopausal women (58 patients/study arm) with histologically confirmed, operable breast cancer presenting to Duke University Medical Center (DUMC) will be enrolled in this trial following completion of primary therapy (including surgery, radiation therapy, and chemotherapy). After baseline assessments, eligible participants will be randomized to one of two supervised aerobic training interventions (moderate-intensity or moderate/high-intensity aerobic training) or an attention-control group (progressive stretching). The aerobic training interventions will include 150 mins.wk<sup>-1 </sup>of supervised treadmill walking per week at an intensity of 60%-70% (moderate-intensity) or 60% to 100% (moderate to high-intensity) of the individually determined peak oxygen consumption (VO<sub>2peak</sub>) between 20-45 minutes/session for 16 weeks. The progressive stretching program will be consistent with the exercise interventions in terms of program length (16 weeks), social interaction (participants will receive one-on-one instruction), and duration (20-45 mins/session). The primary study endpoint is VO<sub>2peak</sub>, as measured by an incremental cardiopulmonary exercise test. Secondary endpoints include physiologic determinants that govern VO<sub>2peak</sub>, patient-reported outcomes, and biomarkers associated with breast cancer recurrence/mortality. All endpoints will be assessed at baseline and after the intervention (16 weeks).</p> <p>Discussion</p> <p>EXCITE is designed to investigate the intensity of aerobic training required to induce optimal improvements in VO<sub>2peak </sub>and other pertinent outcomes in women who have completed definitive adjuvant therapy for operable breast cancer. Overall, this trial will inform and refine exercise guidelines to optimize recovery in breast and other cancer survivors following the completion of primary cytotoxic therapy.</p> <p>Trial Registration</p> <p>NCT01186367</p
Continuous symmetry of C60 fullerene and its derivatives
Conventionally, the Ih symmetry of fullerene C60 is accepted which is
supported by numerous calculations. However, this conclusion results from the
consideration of the molecule electron system, of its odd electrons in
particular, in a close-shell approximation without taking the electron spin
into account. Passing to the open-shell approximation has lead to both the
energy and the symmetry lowering up to Ci. Seemingly contradicting to a
high-symmetry pattern of experimental recording, particularly concerning the
molecule electronic spectra, the finding is considered in the current paper
from the continuous symmetry viewpoint. Exploiting both continuous symmetry
measure and continuous symmetry content, was shown that formal Ci symmetry of
the molecule is by 99.99% Ih. A similar continuous symmetry analysis of the
fullerene monoderivatives gives a reasonable explanation of a large variety of
their optical spectra patterns within the framework of the same C1 formal
symmetry exhibiting a strong stability of the C60 skeleton.Comment: 11 pages. 5 figures. 6 table
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