343 research outputs found
Effect of egg turning and incubation time on carbonic anhydrase gene expression in the blastoderm of the Japanese quail (Coturnix c. japonica)
(1) The gene expression of carbonic anhydrase, a key enzyme for the production sub-embryonic fluid (SEF), was assessed in turned and unturned eggs of the Japanese quail. The plasma membrane-associated isoforms CA IV, CAIX, CA XII, CA XIV, and the cytoplasmic isoform CA II, were
investigated in the extra-embryonic tissue of the blastoderm and in embryonic blood.
(2) Eggs were incubated at 37.6C, c. 60% R.H., and turned hourly (90 ) or left unturned. From 48 to 96 hours of incubation mRNA was extracted from blastoderm tissue, reverse-transcribed to cDNA and quantified by real-time qPCR using gene-specific primers. Blood collected at 96h was processed identically.
(3) Blastoderm CAIV gene expression increased with the period of incubation only in turned eggs, with maxima at 84 and 96h of incubation. Only very low levels were found in blood.
(4) Blastoderm CA II gene expression was greatest at 48 and 54h of incubation, subsequently declining to much lower levels and una ected by turning. Blood CA II gene expression was about 25-fold greater than that in the blastoderm.
(5) The expression of CA IX in the blastoderm was the highest of all isoforms, yet unaffected by turning.
CA XII did not amplify and CA XIV was present at unquantifiable low levels.
(6) It is concluded that solely gene expression for CA IV is sensitive to egg turning, and that increased CA IV gene expression could account for the additional SEF mass found at 84-96h of incubation.
in embryos of turned eggs
Spectroscopy and Stellar Populations of Star-forming Galaxies at z~3 in the Hubble Deep Field - South
We present results of VLT/FORS2 spectroscopy of galaxies at z~3 in the Hubble
Deep Field-South (HDF-S). A sample of galaxies was drawn from the photo-z
catalogue based on the HST/WFPC2 optical images and the deep near-infrared
images obtained with VLT/ISAAC as a part of the FIRES project. We selected
galaxies with photometric redshift between 2.5 and 4. Most of the selected
galaxies are bright in rest-frame UV wavelengths and satisfy color selection
criteria of Lyman break galaxies (LBGs) at z~3. The number of target galaxies
with I(AB)<25.0 was 15. We identified new 5 firm and 2 probable redshifts in
addition to confirmations of previously known 6 galaxies at z~3. We found 6
among these 13 galaxies lie at a quite narrow redshift range at z = 2.80+-0.01.
We examined stellar populations of the galaxies with spectroscopic redshifts
through comparisons of their optical and near-IR photometry data with template
spectra generated by a population synthesis code. The ages from the onset of
star formation for these star-forming galaxies with I<=25.0 are typically
50-200 Myr, and their stellar masses are between (0.5-5) x 10^10 M_sun,
consistent with previous studies. We also compared these SED fitting results
with those for distant red galaxies (DRGs) at z>2 discovered by FIRES. DRGs
have larger stellar masses, larger dust attenuation than our UV-luminous LBG
sample, and their star formation rates are often comparable to LBGs. These
trends suggest that majority of DRGs are indeed the most massive systems at the
redshift and are still in the active star-forming phase. Unless the number
density of DRGs is much smaller than LBGs, estimates based on UV selected
sample could miss substantial part of stellar mass density at z~3.Comment: 13 pages, 10 Postscript figures, accepted for publication in A&
Kingdon's Multiple Streams Approach in new political contexts: Consolidation, configuration, and new findings
There is a need to conduct more diverse cross-case analyses in the Multiple Streams Approach (MSA) literature which originated in the United States, to show how key concepts, such as a windows-of-opportunity and the role of policy entrepreneurs, manifest in different political contexts. We apply Qualitative Comparative Analysis for a cross-case analysis of a unique dataset representing 20 countries from four continents. This approach allows us to highlight distinct pathways to influencing policies. We identify four configurations for expanding civic spaces and two configurations for changing policies. We identify three findings novel to MSA: there are two distinctive policy entrepreneur roles involving local and international civil society actors; effective entrepreneurship is conditional on strengthening civic voice and creating civic space conducive to advocacy; and, therefore, effective entrepreneurs often must focus on expanding the civic space to discuss policy problems and the technical and political feasibility of policy solution
Local galaxy flows within 5 Mpc
We present Hubble Space Telescope/WFPC2 images of sixteen dwarf galaxies as
part of our snapshot survey of nearby galaxy candidates. We derive their
distances from the luminosity of the tip of the red giant branch stars with a
typical accuracy of ~12%. The resulting distances are 4.26 Mpc (KKH 5), 4.74
Mpc (KK 16), 4.72 Mpc (KK 17), 4.66 Mpc (ESO 115-021), 4.43 Mpc (KKH 18), 3.98
Mpc (KK 27), 4.61 Mpc (KKH 34), 4.99 Mpc (KK 54), 4.23 Mpc (ESO 490-017), 4.90
Mpc (FG 202), 5.22 Mpc (UGC 3755), 5.18 Mpc (UGC 3974), 4.51 Mpc (KK 65), 5.49
Mpc (UGC 4115), 3.78 Mpc (NGC 2915), and 5.27 Mpc (NGC 6503). Based on
distances and radial velocities of 156 nearby galaxies, we plot the local
velocity-distance relation, which has a slope of H_0 = 73 km/(c * Mpc) and a
radial velocity dispersion of 85 km/s. When members of the M81 and CenA groups
are removed, and distance errors are taken into account, the radial velocity
dispersion drops to sigma_v=41 km/s. The local Hubble flow within 5 Mpc exibits
a significant anisotropy, with two infall peculiar velocity regions directed
towards the Supergalactic poles. However, two observed regions of outflow
peculiar velocity, situated on the Supergalactic equator, are far away (~50
degr.) from the Virgo/anti-Virgo direction, which disagrees with a spherically
symmetric Virgo-centric flow. About 63% of galaxies within 5 Mpc belong to
known compact and loose groups. Apart from them, we found six new probable
groups, consisting entirely of dwarf galaxies.Comment: 22 pages, 7 figures. A&A Accepted. High resolution Figures 1 and 2
(9616k) are available at http://www.sao.ru/~sme/figs.tar.g
Effect of end-stage renal disease on B-lymphocyte subpopulations, IL-7, BAFF and BAFF receptor expression
Background. End-stage renal disease (ESRD) results in increased susceptibility to infections, impaired response to vaccination and diffuse B-cell lymphopenia. However, the precise nature and mechanism of ESRD-induced B-cell lymphopenia remains unclear. Therefore, we studied the distribution of major B-cell subsets, B-cell growth, differentiation and survival factors, IL-7 and BAFF, and their receptors in 21 haemodialysis patients and 21 controls
Granulocyte-Colony Stimulating Factor (G-CSF) Improves Motor Recovery in the Rat Impactor Model for Spinal Cord Injury
Granulocyte-colony stimulating factor (G-CSF) improves outcome after experimental SCI by counteracting apoptosis, and enhancing connectivity in the injured spinal cord. Previously we have employed the mouse hemisection SCI model and studied motor function after subcutaneous or transgenic delivery of the protein. To further broaden confidence in animal efficacy data we sought to determine efficacy in a different model and a different species. Here we investigated the effects of G-CSF in Wistar rats using the New York University Impactor. In this model, corroborating our previous data, rats treated subcutaneously with G-CSF over 2 weeks show significant improvement of motor function
A threshold level of NFATc1 activity facilitates thymocyte differentiation and opposes notch-driven leukaemia development.
International audienceNFATc1 plays a critical role in double-negative thymocyte survival and differentiation. However, the signals that regulate Nfatc1 expression are incompletely characterized. Here we show a developmental stage-specific differential expression pattern of Nfatc1 driven by the distal (P1) or proximal (P2) promoters in thymocytes. Whereas, preTCR-negative thymocytes exhibit only P2 promoter-derived Nfatc1beta expression, preTCR-positive thymocytes express both Nfatc1beta and P1 promoter-derived Nfatc1alpha transcripts. Inducing NFATc1alpha activity from P1 promoter in preTCR-negative thymocytes, in addition to the NFATc1beta from P2 promoter impairs thymocyte development resulting in severe T-cell lymphopenia. In addition, we show that NFATc1 activity suppresses the B-lineage potential of immature thymocytes, and consolidates their differentiation to T cells. Further, in the pTCR-positive DN3 cells, a threshold level of NFATc1 activity is vital in facilitating T-cell differentiation and to prevent Notch3-induced T-acute lymphoblastic leukaemia. Altogether, our results show NFATc1 activity is crucial in determining the T-cell fate of thymocytes
Sustained supplementation and monitored response with differing carotenoid formulations in early age-related macular degeneration
PURPOSE: To compare the impact of sustained supplementation using different macular carotenoid formulations on macular pigment (MP) and visual function in early age-related macular degeneration (AMD). PATIENTS AND METHODS: Sixty-seven subjects with early AMD were randomly assigned to: Group 1 (20 mg per day lutein (L), 0.86 mg per day zeaxanthin (Z); Ultra Lutein), Group 2 (10 mg per day meso-zeaxanthin (MZ), 10 mg per day L, 2 mg per day Z; Macushield; Macuhealth), Group 3 (17 mg per day MZ, 3 mg per day L, 2 mg per day Z). MP was measured using customised heterochromatic flicker photometry and visual function was assessed by measuring contrast sensitivity (CS) and best-corrected visual acuity (BCVA). AMD was graded using the Wisconsin Age-Related Maculopathy Grading System (AREDS 11-step severity scale). RESULTS: At 3 years, a significant increase in MP from baseline was observed in all groups at each eccentricity (P<0.05), except at 1.75° in Group 1 (P=0.160). Between 24 and 36 months, significant increases in MP at each eccentricity were seen in Group 3 (P<0.05 for all), and at 0.50° in Group 2 (P<0.05), whereas no significant increases were seen in Group 1 (P>0.05 for all). At 36 months, compared with baseline, the following significant improvements (P<0.05) in CS were observed: Group 2—1.2, 6, and 9.6 cycles per degree (c.p.d.); Group 1—15.15 c.p.d.; and Group 3—6, 9.6, and 15.15 c.p.d. No significant changes in BCVA, or progression to advanced AMD, were observed. CONCLUSION: In early AMD, MP can be augmented with a variety of supplements, although the inclusion of MZ may confer benefits in terms of panprofile augmentation and in terms of CS enhancement
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