Dynamic protein methylation in chromatin biology

Post-translational modification of chromatin is emerging as an increasingly important regulator of chromosomal processes. In particular, histone lysine and arginine methylation play important roles in regulating transcription, maintaining genomic integrity, and contributing to epigenetic memory. Recently, the use of new approaches to analyse histone methylation, the generation of genetic model systems, and the ability to interrogate genome wide histone modification profiles has aided in defining how histone methylation contributes to these processes. Here we focus on the recent advances in our understanding of the histone methylation system and examine how dynamic histone methylation contributes to normal cellular function in mammals

Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society

Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society

Avaliação de larvicidas de origem microbiana no controle da traça-das-crucíferas em couve-flor Evaluation of microbiological larvicides to control diamondback moth in cauliflower

Dois inseticidas biológicos à base de Bacillus thuringiensis subspécies kurstaki (Btk) e aizawai (Bta) e um inseticida não sistêmico de origem biológica, à base de spinosad, foram avaliados em campo contra a traça-das-crucíferas, Plutella xylostella (L.)(Lep.: Plutellidae), em cultivo de couve-flor. O experimento foi realizado em Brazlândia, DF, em uma área de produção regular de hortaliças. A lavoura foi conduzida segundo manejo indicado para a região, sem qualquer intervenção que não o controle da praga. O experimento foi realizado no período de julho a setembro de 2002. O delineamento foi de blocos ao acaso, com quatro tratamentos e quatro repetições. Os produtos foram aplicados em função da média do número de furos produzidos pela praga, presentes nas quatro folhas centrais das plantas, sendo os diferentes tratamentos avaliados semanalmente. Quando a média do número de furos atingia valor igual ou superior a seis, os produtos eram aplicados. Adotando-se este procedimento, aplicou-se três vezes o inseticida spinosad e seis vezes os inseticidas Btk e Bta. Os três tratamentos com inseticidas não diferiram entre si, mas diferiram significativamente da testemunha quanto à produção. As áreas tratadas com Btk produziram 78,1% de cabeças comercializáveis, as tratadas com Bta 76,5% e as tratadas com spinosad 75,5%. No controle houve perda de 34,4% da produção. A utilização dos produtos aumentou a receita da cultura da couve-flor em relação à testemunha, nos valores de R$2.505,19 com o Btk, R$ 1.954,55 com o Bta e R$1.891,65 com spinosad.<br>Two bioinsecticides based on Bacillus thuringiensis sub species kurstaki (Btk) and aizawai (Bta) and non-systemic insecticide of biological origin based on spinosad were evaluated on cauliflower crop for diamondback moth, Plutella xylostella (L.) (Lep.:Plutellidae) control. The experiment was conducted in a vegetable production area of Brazlândia, Brazil. The crop was conducted using the same technology of production adopted by farmers for pest control management. The experiment was conducted between July and September 2002. Randomized blocks with four treatments and four replications were used. Six holes per plant in the four central leaves, were used as a parameter to indicate the necessity of applying insecticides. The number of holes was evaluated weekly. Based on this parameter spinosad was applied three times and Btk and Bta six times. Similar results were obtained in the treatments using insecticides. However significant differences in production were observed between treatments in which insecticide was used and the untreated control. The area treated with Btk produced 78.1$ 785.32; for Btk U$592.99 for spinosal and U$ 612.71 for Bta