310 research outputs found
Persistency in Lolium x Festuca Hybrid Derivatives and its Relationships with Flowering Traits
Using amphiploid and backcrossed derivatives of Italian ryegrass x tall fescue hybrids, the paper emphasizes the interest of introgression vs amphiploidization in breeding for specific traits such as persistency or seed production from tall fescue or ryegrass resp. Persistency in amphiploid and Lolium-introgressed progenies were assessed in nursery together with variation of flowering traits. Persistency was found lower, on average, in introgressed progenies than in hybrid progenies but with enlarged variability within progeny suggesting possible advantageous rearrangements of fescue chromosomes. Although significantly associated, persistency in both populations was only very little affected by the variations in flowering traits such as flowering date, number of heads in Spring and reheading in Summer. As these traits are related to seed productivity to some extent, it is suggested that selecting for both high persistency and high seed production potential should not be incompatible and could be successfully applied in tetraploid introgressive population resulting from one single backcross of hybrid into ryegrass
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
Prophylaxis of infectious complications with colony-stimulating factors in adult cancer patients undergoing chemotherapy—evidence-based guidelines from the Infectious Diseases Working Party AGIHO of the German Society for Haematology and Medical Oncology (DGHO)
We found convincing evidence from numerous randomised controlled trials that G-CSF, biosimilar G-CSF and pegfilgrastim reduce the risk to develop febrile neutropenia and infections. As a rule of thumb, it seems the relative benefit is highest for patients with an intermediate risk of infections. Compared to other guidelines, we rated the evidence for growth factors during AML induction chemotherapy and pegfilgrastim use in haematological malignancies lowe
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&
Fully Bayesian tests of neutrality using genealogical summary statistics
<p>Abstract</p> <p>Background</p> <p>Many data summary statistics have been developed to detect departures from neutral expectations of evolutionary models. However questions about the neutrality of the evolution of genetic loci within natural populations remain difficult to assess. One critical cause of this difficulty is that most methods for testing neutrality make simplifying assumptions simultaneously about the mutational model and the population size model. Consequentially, rejecting the null hypothesis of neutrality under these methods could result from violations of either or both assumptions, making interpretation troublesome.</p> <p>Results</p> <p>Here we harness posterior predictive simulation to exploit summary statistics of both the data and model parameters to test the goodness-of-fit of standard models of evolution. We apply the method to test the selective neutrality of molecular evolution in non-recombining gene genealogies and we demonstrate the utility of our method on four real data sets, identifying significant departures of neutrality in human influenza A virus, even after controlling for variation in population size.</p> <p>Conclusion</p> <p>Importantly, by employing a full model-based Bayesian analysis, our method separates the effects of demography from the effects of selection. The method also allows multiple summary statistics to be used in concert, thus potentially increasing sensitivity. Furthermore, our method remains useful in situations where analytical expectations and variances of summary statistics are not available. This aspect has great potential for the analysis of temporally spaced data, an expanding area previously ignored for limited availability of theory and methods.</p
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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