260 research outputs found
Prediction of Seed Yield of Festuca x Lolium Hybrids from the Nursery Mother Plants
In order to develop commercial Festuca x Lolium hybrids, their seed production has to be improved. Seed yields of Festuca x Lolium progenies were assessed in dense plots. Prediction of those seed yields was based on the morphological observations done on spaced plants in the nursery of both mother plants and their progenies. The best prediction of the progeny seed yields is a linear regression on the stem density and the seed weight per inflorescence assessed on the mother plants
Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps.
A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone, (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination which points at a polygenic architecture of female choice with strong environmental influences
Identifying frequency decorrelated dust residuals in B-mode maps by exploiting the spectral capability of bolometric interferometry
Astrophysical polarized foregrounds represent the most critical challenge in
Cosmic Microwave Background (CMB) B-mode experiments. Multi-frequency
observations can be used to constrain astrophysical foregrounds to isolate the
CMB contribution. However, recent observations indicate that foreground
emission may be more complex than anticipated.
We investigate how the increased spectral resolution provided by band
splitting in Bolometric Interferometry (BI) through a technique called spectral
imaging can help control the foreground contamination in the case of
unaccounted Galactic dust frequency decorrelation along the line-of-sight.
We focus on the next generation ground-based CMB experiment CMB-S4, and
compare its anticipated sensitivities, frequency and sky coverage with a
hypothetical version of the same experiment based on BI. We perform a
Monte-Carlo analysis based on parametric component separation methods (FGBuster
and Commander) and compute the likelihood on the recovered tensor-to-scalar
ratio.
The main result of this analysis is that spectral imaging allows us to detect
systematic uncertainties on r from frequency decorrelation when this effect is
not accounted for in component separation. Conversely, an imager would detect a
biased value of r and would be unable to spot the presence of a systematic
effect. We find a similar result in the reconstruction of the dust spectral
index, where we show that with BI we can measure more precisely the dust
spectral index also when frequency decorrelation is present.
The in-band frequency resolution provided by BI allows us to identify dust
LOS frequency decorrelation residuals where an imager of similar performance
would fail. This opens the prospect to exploit this potential in the context of
future CMB polarization experiments that will be challenged by complex
foregrounds in their quest for B-modes detection.Comment: 13 Pages, 15 figures, 4 tables. Submitted to A&
Good manufacturing practice production of CD34+ progenitor-derived NK cells for adoptive immunotherapy in acute myeloid leukemia
Allogeneic natural killer (NK) cell-based immunotherapy is a promising, well-tolerated adjuvant therapeutic approach for acute myeloid leukemia (AML). For reproducible NK cell immunotherapy, a homogenous, pure and scalable NK cell product is preferred. Therefore, we developed a good manufacturing practice (GMP)-compliant, cytokine-based ex vivo manufacturing process for generating NK cells from CD3
Travelling in time with networks: revealing present day hybridization versus ancestral polymorphism between two species of brown algae, Fucus vesiculosus and F. spiralis
Background: Hybridization or divergence between sympatric sister species provides a natural laboratory to study speciation processes. The shared polymorphism in sister species may either be ancestral or derive from hybridization, and the accuracy of analytic methods used thus far to derive convincing evidence for the occurrence of present day hybridization is largely debated.
Results: Here we propose the application of network analysis to test for the occurrence of present day hybridization between the two species of brown algae Fucus spiralis and F. vesiculosus. Individual-centered networks were analyzed on the basis of microsatellite genotypes from North Africa to the Pacific American coast, through the North Atlantic. Two genetic distances integrating different time steps were used, the Rozenfeld (RD;
based on alleles divergence) and the Shared Allele (SAD; based on alleles identity) distances. A diagnostic level of genotype divergence and clustering of individuals from each species was obtained through RD while screening for exchanges through putative hybridization was facilitated using SAD. Intermediate individuals linking both clusters on the RD network were those sampled at the limits of the sympatric zone in Northwest Iberia. Conclusion: These results suggesting rare hybridization were confirmed by simulation of hybrids and F2 with directed backcrosses. Comparison with the Bayesian method STRUCTURE confirmed the usefulness of both approaches and emphasized the reliability of network analysis to unravel and study hybridization
LiteBIRD Science Goals and Forecasts. A Case Study of the Origin of Primordial Gravitational Waves using Large-Scale CMB Polarization
We study the possibility of using the satellite -mode survey to
constrain models of inflation producing specific features in CMB angular power
spectra. We explore a particular model example, i.e. spectator axion-SU(2)
gauge field inflation. This model can source parity-violating gravitational
waves from the amplification of gauge field fluctuations driven by a
pseudoscalar "axionlike" field, rolling for a few e-folds during inflation. The
sourced gravitational waves can exceed the vacuum contribution at reionization
bump scales by about an order of magnitude and can be comparable to the vacuum
contribution at recombination bump scales. We argue that a satellite mission
with full sky coverage and access to the reionization bump scales is necessary
to understand the origin of the primordial gravitational wave signal and
distinguish among two production mechanisms: quantum vacuum fluctuations of
spacetime and matter sources during inflation. We present the expected
constraints on model parameters from satellite simulations, which
complement and expand previous studies in the literature. We find that
will be able to exclude with high significance standard single-field
slow-roll models, such as the Starobinsky model, if the true model is the
axion-SU(2) model with a feature at CMB scales. We further investigate the
possibility of using the parity-violating signature of the model, such as the
and angular power spectra, to disentangle it from the standard
single-field slow-roll scenario. We find that most of the discriminating power
of will reside in angular power spectra rather than in and
correlations.Comment: 22 pages, 13 figures. Submitted to JCA
Status of QUBIC, the Q&U Bolometer for Cosmology
The Q&U Bolometric Interferometer for Cosmology (QUBIC) is a novel kind of
polarimeter optimized for the measurement of the B-mode polarization of the
Cosmic Microwave Back-ground (CMB), which is one of the major challenges of
observational cosmology. The signal is expected to be of the order of a few
tens of nK, prone to instrumental systematic effects and polluted by various
astrophysical foregrounds which can only be controlled through multichroic
observations. QUBIC is designed to address these observational issues with a
novel approach that combines the advantages of interferometry in terms of
control of instrumental systematics with those of bolometric detectors in terms
of wide-band, background-limited sensitivity.Comment: Contribution to the 2022 Cosmology session of the 33rd Rencontres de
Blois. arXiv admin note: substantial text overlap with arXiv:2203.0894
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