2,166 research outputs found
Recombinant Measles Viruses Defective for RNA Editing and V Protein Synthesis Are Viable in Cultured Cells
AbstractThe measles virus (MV) phosphoprotein (P) gene encodes three proteins, P, C, and V. The V protein is synthesized by pseudo-templated transcription, also designated as RNA editing: during P gene transcription one G residue is inserted at a defined position in about 50% of the mRNAs. To study the importance of sequence elements for the nontemplated G insertion, we generated recombinant MVs in which six different mutations were introduced within the region where editing occurs (3′ UUUUUCCC, template strand). These viruses were then analyzed for their ability to edit their P mRNA and to produce V protein. Single U to C changes within the U stretch abolished editing. Extending the template by three C residues at the site of G insertion resulted in a less precise editing phenotype and overproduction of V. None of these mutants were impaired in their multiplication behavior when analyzed in cultured cells. However, the syncytia of a recombinant MV overproducing V protein were in general smaller and lysed 1 to 2 days later than usual
Teachers’ Perceptions of Childcare and Preschool Expulsion
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142342/1/chso12228_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142342/2/chso12228.pd
Effects of aging on identifying emotions conveyed by point-light walkers
M.G. was supported by EC FP7 HBP (grant 604102), PITN-GA-011-290011 (ABC) FP7-ICT-2013-10/ 611909 (KOROIBOT), and by GI 305/4-1 and KA 1258/15-1, and BMBF, FKZ: 01GQ1002A. K.S.P. was supported by a BBSRC New Investigator Grant. A.B.S. and P.J.B. were supported by an operating grant (528206) from the Canadian Institutes for Health Research. The authors also thank Donna Waxman for her valuable help in data collection for all experiments described here.Peer reviewedPostprin
The elemental composition of the Sun I. The intermediate mass elements Na to Ca
The composition of the Sun is an essential piece of reference data for
astronomy, cosmology, astroparticle, space and geo-physics. This article,
dealing with the intermediate-mass elements Na to Ca, is the first in a series
describing the comprehensive re-determination of the solar composition. In this
series we severely scrutinise all ingredients of the analysis across all
elements, to obtain the most accurate, homogeneous and reliable results
possible. We employ a highly realistic 3D hydrodynamic solar photospheric
model, which has successfully passed an arsenal of observational diagnostics.
To quantify systematic errors, we repeat the analysis with three 1D hydrostatic
model atmospheres (MARCS, MISS and Holweger & M\"{u}ller 1974) and a
horizontally and temporally-averaged version of the 3D model
(3D). We account for departures from LTE wherever possible.
We have scoured the literature for the best transition probabilities, partition
functions, hyperfine and other data, and stringently checked all observed
profiles for blends. Our final 3D+NLTE abundances are:
,
,
,
,
, , and
. The uncertainties include both
statistical and systematic errors. Our results are systematically smaller than
most previous ones with the 1D semi-empirical Holweger & M\"uller model. The
3D model returns abundances very similar to the full 3D
calculations. This analysis provides a complete description and a slight update
of the Na to Ca results presented in Asplund, Grevesse, Sauval & Scott
(arXiv:0909.0948), with full details of all lines and input data.Comment: 7 figures, 14 pages + 5 online-only pages of tables and an appendix.
v2. Matches version accepted by A&
The influence of electron collisions on non-LTE Li line formation in stellar atmospheres
The influence of the uncertainties in the rate coefficient data for
electron-impact excitation and ionization on non-LTE Li line formation in cool
stellar atmospheres is investigated. We examine the electron collision data
used in previous non-LTE calculations and compare them to recent calculations
that use convergent close-coupling (CCC) techniques and to our own calculations
using the R-matrix with pseudostates (RMPS) method. We find excellent agreement
between rate coefficients from the CCC and RMPS calculations, and reasonable
agreement between these data and the semi-empirical data used in non-LTE
calculations up to now. The results of non-LTE calculations using the old and
new data sets are compared and only small differences found: about 0.01 dex (~
2%) or less in the abundance corrections. We therefore conclude that the
influence on non-LTE calculations of uncertainties in the electron collision
data is negligible. Indeed, together with the collision data for the charge
exchange process Li(3s) + H Li^+ + H^- now available, and barring the
existence of an unknown important collisional process, the collisional data in
general is not a source of significant uncertainty in non-LTE Li line formation
calculations.Comment: 8 pages, accepted by Astronomy and Astrophysics; Replaced with minor
corrections following proof
Inorganic Amino-Nitro-Guanidinium Derivatives
1-Amino-3-nitroguanidine (ANQ, 1) was synthesized by hydrazinolysis of nitroguanidine (NQ) with hydrazine hydrate. Four different amino-nitroguanidinium salts (chloride (2), bromide (3), iodide (4) and sulfate (5)) were synthesized and structurally characterized by low-temperature X-ray diffraction. The halides 2–4 could only be obtained crystalline as monohydrates. In addition, they were characterized by NMR and vibrational spectroscopy, elemental analysis and the sensitivities towards impact, friction and electrostatic discharge were determined. The compounds can be used in silver (AgX, X = Cl, Br, I) and barium (BaSO4) based metathesis reactions in order to form more complex salts of 1-amino-nitroguanidine
Health-Related Fitness and Energy Expenditure in Recreational Youth Rock Climbers 8-16 Years of Age
International Journal of Exercise Science 8(2): 174-183, 2015. Information on the characteristics of youth rock climbers is minimal. The purpose was to 1) Determine the influence of a three-month program of bouldering and vertical rock climbing on the anthropometry and health-related physical fitness of relatively novice youth climbers, and 2) determine whether rock climbing and bouldering in novice youth climbers can provide adequate levels of moderate to vigourous physical activity (US DHHS, 2008). Fifteen participants (11 males and 4 females; mean age = 11.5 ± 2.3 years) from a newly established youth climbing team were assessed twice weekly during their normal two-hour training sessions at a local rock gym. Body composition, flexibility, grip strength, and anthropometric estimates of somatotype were measured in August and November. Heart rate (HR) monitors recorded average activity heart rate (AHR), peak heart rate (HRpeak), and estimated energy expended (EE-kcals) during each climbing session. Basic descriptive statistics were run; repeat measure ANOVAs were used to assess changes between times. Estimated percent body fat did not change, but individual skinfolds (biceps and supraspinale) decreased significantly (
Osteopontin: an early innate immune marker of Escherichia coli mastitis harbors genetic polymorphisms with possible links with resistance to mastitis
<p>Abstract</p> <p>Background</p> <p>Mastitis is the most important disease in dairy cows and it causes significant lost of profit to producers. Identification of the genes, and their variants, involved in innate immune responses is essential for the understanding of this inflammatory disease and to identify potential genetic markers for resistance to mastitis. The progeny of dairy cows would benefit from receiving favourable alleles that support greater resistance to infection, thus reducing antibiotic use. This study aims to identify a key gene in the innate immune response to mastitis, led us to evaluate its genetic association with somatic cell score (SCS), which is an indicator of clinical mastitis, and to evaluate its impact on other traits related to milk production.</p> <p>Results</p> <p>The osteopontin transcript (<it>SPP1</it>) was identified in the somatic cells from cows experimentally infected with <it>Escherichia coli</it>. By selecting bulls with extreme estimated breeding values (EBVs) for SCS, which is an indicator of mammary gland health, four DNA polymorphisms in the <it>SPP1 </it>genomic sequence were found. Statistical analysis revealed that the SNP <it>SPP1c.-1301G>A </it>has an impact on EBV for SCS (<it>P </it>< 0.001) Using an allele substitution model, <it>SPP1c.-1251C>T</it>, <it>SPP1c.-430G>A</it>, and <it>SPP1c.*40A>C </it>have an impact on SCS whereas <it>SPP1c.-1301G>A </it>has an effect on the EBVs for milk yield (second and third lactations), fat and protein percentages (all three lactations). Analysis revealed statistically significant differences between haplotype groups at a comparison-wise level with sire EBVS for SCS for the first (<it>P </it>= 0.012), second (<it>P </it>< 0.001), and third (<it>P </it>< 0.001) lactations.</p> <p>Conclusion</p> <p>This study reports the link between DNA polymorphisms of <it>SPP1</it>, the number of milk immune cells and, potentially, the susceptibility to mastitis. These SNPs were identified by <it>in silico </it>search to be located in transcription factor recognition sites which factors are presumably involved in the Th1 immune response and in the Th2 regulation pathway. Indeed, one SNP abolished the SP1 recognition site, whereas another SNP affected the transcription binding factor IKAROS. All together, these findings support the genetic potential of these variants in terms of selection for the improvement of mastitis resistance in dairy cows.</p
Navigating the Range of Statistical Tools for Inferential Network Analysis
The last decade has seen substantial advances in statistical techniques for the analysis of network data, as well as a major increase in the frequency with which these tools are used. These techniques are designed to accomplish the same broad goal, statistically valid inference in the presence of highly interdependent relationships, but important differences remain between them. We review three approaches commonly used for inferential network analysis—the quadratic assignment procedure, exponential random graph models, and latent space network models—highlighting the strengths and weaknesses of the techniques relative to one another. An illustrative example using climate change policy network data shows that all three network models outperform standard logit estimates on multiple criteria. This article introduces political scientists to a class of network techniques beyond simple descriptive measures of network structure, and it helps researchers choose which model to use in their own research
Atmospheric ice nuclei in the Eyjafjallajökull volcanic ash plume
We have sampled atmospheric ice nuclei (IN) and aerosol in Germany and in Israel during spring 2010. IN were analyzed by the static vapor diffusion chamber FRIDGE, as well as by electron microscopy. During the Eyjafjallajökull volcanic eruption of April 2010 we have measured the highest ice nucleus number concentrations (>600 l−1) in our record of 2 yr of daily IN measurements in central Germany. Even in Israel, located about 5000 km away from Iceland, IN were as high as otherwise only during desert dust storms. The fraction of aerosol activated as ice nuclei at −18 °C and 119% rhice and the corresponding area density of ice-active sites per aerosol surface were considerably higher than what we observed during an intense outbreak of Saharan dust over Europe in May 2008.
Pure volcanic ash accounts for at least 53–68% of the 239 individual ice nucleating particles that we collected in aerosol samples from the event and analyzed by electron microscopy. Volcanic ash samples that had been collected close to the eruption site were aerosolized in the laboratory and measured by FRIDGE. Our analysis confirms the relatively poor ice nucleating efficiency (at −18 °C and 119% ice-saturation) of such "fresh" volcanic ash, as it had recently been found by other workers. We find that both the fraction of the aerosol that is active as ice nuclei as well as the density of ice-active sites on the aerosol surface are three orders of magnitude larger in the samples collected from ambient air during the volcanic peaks than in the aerosolized samples from the ash collected close to the eruption site. From this we conclude that the ice-nucleating properties of volcanic ash may be altered substantially by aging and processing during long-range transport in the atmosphere, and that global volcanism deserves further attention as a potential source of atmospheric ice nuclei
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