Early assessment of genotypic variation in growth and nitrogen fixation in Faidherbia albida/rhizobium symbiosis

To enhance the benefits from N2-fixing symbiosis in low nitrogen fixers such as Faidherbia albida, knowledge is needed on how genotypes of both the host and its bacterial partner interact to influence N fixation-related traits of the host legume. A greenhouse experiment was carried out to investigate the variability of several traits with respect to provenance, rhizobial strain and their interactions. Four West African provenances of F. albida were inoculated with five proven effective strains and grown for two months. Provenance x strain interactions were significant only for shoot N concentration (%N) and total shoot N uptake but their contributions to total phenotypic variances were rather low (6-10%). Because of large differencesamong provenances in growth performance the host genotype showed the greatest contribution (70.7%) to the variability in total shoot N uptake. Variability in %N in turn was mostly related to strain effectiveness (71.2%).These results suggest that under conditions of N deficiency, growth performance and shoot N concentration provide reliable selection criteria when screening for improved N2-fixation in F. albida.Keywords: rhizobia, Faidherbia, provenance, variability, interaction, N2-fixatio

The effects of seasons on cholesterol content and fatty acid compositions of muscle of Helix aspersa living in Konya, Turkey

Background: The aim of the present study is the determination of the effects of seasonal variations on the proximate analysis, cholesterol content and fatty acid compositions of Helix aspersa.Materials and Methods: Garden snails (Helix aspersa) were picked up by hand from the Central Anatolia Region of Turkey, in autumn (November) and spring (April) in 2011. Fatty acid methyl esters (FAMEs) and cholesterol analysis were analyzed by gas chromatography (GC). The protein contents of snail muscle were determined with Kjeldahl distillation units. Statistical comparisons were made by using SPSS Software (version 16.0).Results: Thirty different fatty acids of different saturation levels were detected. As the predominant fatty acids, stearic acid (C18:0), oleic acid (C18:1ω9), linoleic acid (C18:2ω6), palmitic acid (C16:0), arachidonic acid (C20:4ω6), eicosadienoic acid (C20:2) and linolenic acid (C18:3ω3) were found in Helix aspersa. Palmitic acid (C16:0) was identified as the major SFA in autumn and spring. Linoleic acid (C18:2ω6), eicosadienoic acid (C20:2) and arachidonic acid (C20:4ω6) have the highest levels among the PUFAs. In the present study, ω3 were found 5.48% and 13.94% in autumn and spring, respectively.Conclusion: Linolenic acid and omega-3 fatty acid amounts in the spring increased significantly but cholesterol content was not affected in Helix aspersa both in season.Key words: Helix aspersa, seasonal variations, fatty acid, SFA, PUFA, cholestero

Voting 'against all' in postcommunist Russia

Since the early 1990s voters in Russia (and most of the other post-Soviet republics) have been offered the opportunity to vote ‘against all’ parties and candidates. Increasing numbers have done so. The evidence of two post-election surveys indicates that ‘against all’ voters are younger than other voters, more urban and more highly educated. They do not reject liberal democracy, but are critical of the contemporary practice of Russian politics and find no parties that adequately reflect their views. With the ending of the ‘against all’ facility in 2006 and other changes in the Russian electoral system under the Putin presidency, levels of turnout are likely to fall further and the protest vote will seek other outlets within or outside the parliamentary system

QT Intervals and Outcome of Pregnancy in Patients with Eclampsia

Background: Eclampsia is associated with considerable mortality and morbidity for the mother and the foetus. QT intervals and dispersions elongations are associated with dangerous arrhythmias and sudden death. Hypocalcaemia is related to both conditions.Aim: To investigate the pattern of QT intervals and dispersions among eclamptic patients and determine outcomes in mother and foetus and also to find out if there is a relationship between the two conditions.Method: Electrocardiograms of 32 patients with intra-partum eclampsia were compared with 30 normal matched for gestational age. Biochemical indices were also compared. Outcome in mother and foetus in the 2 groups were studied.Results: The mean QT intervals and dispersions were comparable in subjects and controls. It was only in QTcmax that there was a significant prolongation in eclamptics (437.87+35.24 vs 420.36+ 32.07 msecs p< 0.05), though the mean QTcmax of the subjects was not absolutelyprolonged. 59.4% of the patients had QTcmax prolonged compared to 13.3% of controls. The QTd and QTcd were prolonged in 18.8% and 15.6% of the patients respectively. No control had a prolongation of these intervals. There were 9(28.1%) foetal deaths in patients compared tonone in controls. None of the QT intervals were related to either maternal or foetal outcome. There was significant difference in serum calcium between patient and control (9.03 +0.41 vs 10.4 + 0.47mg/dl, p < 0.05). The higher the serum calcium, the tendency to better foetal outcome (r=0.83).Conclusion: Many eclamptics had prolonged QT intervals and dispersions but were not associated with dangerous arrhythmias and sudden death

Radio morphologies of planetary nebulae

We have examined the morphologies of planetary nebulae observed in the recent very large array (VLA) surveys. The high angular resolution of the VLA has allowed the.extension of morphological classification to a much more compact population than before. The radio images of planetary nebulae are analyzed in terms of the prolate ellipsoidal shell (PES) model. Simulated radio images are produced using various asymmetry parameters in the PES model. Using these models as a guide, the radio images of planetary nebulae are classified into different morphological classes. No significant differences can be found between the statistics of morphological classes of high surface brightness/compact and low surface brightness/extended planetary nebulae, or with those classified by optical means. We conclude that the morphology of planetary nebulae is determined early in their evolution. The degree of asymmetry planetary nebulae inherited from their asymptotic giant branch progenitors is probably as important in determining the asymmetry observed in planetary nebulae as the shaping done by interacting winds during the planetary nebula phase. © 1996. The American Astronomical Society. All rights reserved.published_or_final_versio

High-resolution radio continuum observations of compact planetary nebulae

We report 15 GHz radio continuum observations of 19 compact planetary nebulae. The high resolution (∼0″.1) images obtained allowed detailed examination of the structures of these nebulae. Most of these objects have very high radio surface brightness temperatures and critical frequencies, suggesting that they are very young planetary nebulae. Most show a "bipolar" central structure, consistent with an ellipsoidal shell viewed at an angle, and may also show extended halo structure outside of the shell, probably representing remnant material left over from the asymptotic giant branch progenitor.published_or_final_versio

Single-cell lineage tracing in the mammary gland reveals stochastic clonal dispersion of stem/progenitor cell progeny.

The mammary gland undergoes cycles of growth and regeneration throughout reproductive life, a process that requires mammary stem cells (MaSCs). Whilst recent genetic fate-mapping studies using lineage-specific promoters have provided valuable insights into the mammary epithelial hierarchy, the true differentiation potential of adult MaSCs remains unclear. To address this, herein we utilize a stochastic genetic-labelling strategy to indelibly mark a single cell and its progeny in situ, combined with tissue clearing and 3D imaging. Using this approach, clones arising from a single parent cell could be visualized in their entirety. We reveal that clonal progeny contribute exclusively to either luminal or basal lineages and are distributed sporadically to branching ducts or alveoli. Quantitative analyses suggest that pools of unipotent stem/progenitor cells contribute to adult mammary gland development. Our results highlight the utility of tracing a single cell and reveal that progeny of a single proliferative MaSC/progenitor are dispersed throughout the epithelium.This work was supported by a grant from the Medical Research Council programme grant no. MR/J001023/1 (B.L-L. and C.J.W). F.M.D. was funded by a National Health and Medical Research Council CJ Martin Biomedical Fellowship (GNT1071074). O.B.H. was funded by a Wellcome Trust PhD studentship (105377/Z/14/Z)

Particle Collisions on Stringy Black Hole Background

The collision of two particles in the background of a Sen black hole is studied. With the equations of motion of the particles, the center-of-mass energy is investigated when the collision takes place at the horizon of a Sen black hole. For an extremal Sen black hole, we find that the center-of-mass energy will be arbitrarily high with two conditions: (1) spin $a\neq 0$ and (2) one of the colliding particles has the critical angular momentum $l_{\text{c}}=2$. For a nonextremal Sen black hole, we show that, in order to obtain an unlimited center-of-mass energy, one of the colliding particles should have the critical angular momentum $l'_{\text{c}}=2 r_{+}/a$ ($r_{+}$ is the radius of the outer horizon for a nonextremal black hole). However, a particle with the angular momentum $l=l'_{\text{c}}$ could not approach the black hole from outside of the horizon through free fall, which implies that the collision with arbitrarily high center-of-mass energy could not take place. Thus, there is an upper bound of the center-of-mass energy for the nonextremal black hole. We also obtain the maximal center-of-mass energy for a near-extremal black hole and the result implies that the Planck-scale energy is hard to be approached. Furthermore, we also consider the back-reaction effects. The result shows that, neglecting the gravitational radiation, it has a weak effect on the center-of-mass energy. However, we argue that the maximum allowed center-of-mass energy will be greatly reduced to below the Planck-scale when the gravitational radiation is included.Comment: 17 pages, 4 figures, published versio