The GOGREEN survey: The environmental dependence of the star-forming galaxy main sequence at 1.0<z<1.51.0<z<1.5

We present results on the environmental dependence of the star-forming galaxy main sequence in 11 galaxy cluster fields at $1.0 < z < 1.5$ from the Gemini Observations of Galaxies in Rich Early Environments Survey (GOGREEN) survey. We use a homogeneously selected sample of field and cluster galaxies whose membership is derived from dynamical analysis. Using [OII]-derived star formation rates (SFRs), we find that cluster galaxies have suppressed SFRs at fixed stellar mass in comparison to their field counterparts by a factor of 1.4 $\pm$ 0.1 ($\sim3.3\sigma$) across the stellar mass range: $9.0 < \log(M_{*} /M_{\odot}) < 11.2$. We also find that this modest suppression in the cluster galaxy star-forming main sequence is mass and redshift dependent: the difference between cluster and field increases towards lower stellar masses and lower redshift. When comparing the distribution of cluster and field galaxy SFRs to the star-forming main sequence, we find an overall shift towards lower SFRs in the cluster population, and note the absence of a tail of high SFR galaxies as seen in the field. Given this observed suppression in the cluster galaxy star-forming main sequence, we explore the implications for several scenarios such as formation time differences between cluster and field galaxies, and environmentally-induced star formation quenching and associated timescales

The GOGREEN survey: Post-infall environmental quenching fails to predict the observed age difference between quiescent field and cluster galaxies at z>1

We study the star formation histories (SFHs) and mass-weighted ages of 331 UVJ-selected quiescent galaxies in 11 galaxy clusters and in the field at 11 has been driven by different physical processes than those at play at z=0

Dynamic Allostery in the Methionine Repressor Revealed by Force Distribution Analysis

Many fundamental cellular processes such as gene expression are tightly regulated by protein allostery. Allosteric signal propagation from the regulatory to the active site requires long-range communication, the molecular mechanism of which remains a matter of debate. A classical example for long-range allostery is the activation of the methionine repressor MetJ, a transcription factor. Binding of its co-repressor SAM increases its affinity for DNA several-fold, but has no visible conformational effect on its DNA binding interface. Our molecular dynamics simulations indicate correlated domain motions within MetJ, and quenching of these dynamics upon SAM binding entropically favors DNA binding. From monitoring conformational fluctuations alone, it is not obvious how the presence of SAM is communicated through the largely rigid core of MetJ and how SAM thereby is able to regulate MetJ dynamics. We here directly monitored the propagation of internal forces through the MetJ structure, instead of relying on conformational changes as conventionally done. Our force distribution analysis successfully revealed the molecular network for strain propagation, which connects collective domain motions through the protein core. Parts of the network are directly affected by SAM binding, giving rise to the observed quenching of fluctuations. Our results are in good agreement with experimental data. The force distribution analysis suggests itself as a valuable tool to gain insight into the molecular function of a whole class of allosteric proteins

GOGREEN: a critical assessment of environmental trends in cosmological hydrodynamical simulations at z ~ 1

Recent observations have shown that the environmental quenching of galaxies at z ∼ 1 is qualitatively different to that in the local Universe. However, the physical origin of these differences has not yet been elucidated. In addition, while low-redshift comparisons between observed environmental trends and the predictions of cosmological hydrodynamical simulations are now routine, there have been relatively few comparisons at higher redshifts to date. Here we confront three state-of-the-art suites of simulations (BAHAMAS+MACSIS, EAGLE+Hydrangea, IllustrisTNG) with state-of-the-art observations of the field and cluster environments from the COSMOS/UltraVISTA and GOGREEN surveys, respectively, at z ∼ 1 to assess the realism of the simulations and gain insight into the evolution of environmental quenching. We show that while the simulations generally reproduce the stellar content and the stellar mass functions of quiescent and star-forming galaxies in the field, all the simulations struggle to capture the observed quenching of satellites in the cluster environment, in that they are overly efficient at quenching low-mass satellites. Furthermore, two of the suites do not sufficiently quench the highest mass galaxies in clusters, perhaps a result of insufficient feedback from AGN. The origin of the discrepancy at low stellar masses (⁠M∗≲1010 M⊙), which is present in all the simulations in spite of large differences in resolution, feedback implementations, and hydrodynamical solvers, is unclear. The next generation of simulations, which will push to significantly higher resolution and also include explicit modelling of the cold interstellar medium, may help us to shed light on the low-mass tension

Raising awareness of the importance of funding for tuberculosis small-molecule research

Tuberculosis (TB) drug discovery research is hampered by several factors, but as in many research areas, the available funding is insufficient to support the needs of research and development. Recent years have seen various large collaborative efforts involving public-private partnerships, mimicking the situation during the golden age of antibiotic drug discovery during the 1950s and 1960s. The large-scale collaborative efforts funded by the European Union (EU) are now subject to diminishing financial support. As a result, TB researchers are increasingly looking for novel forms of funding, such as crowdfunding, to fill this gap. Any potential solution will require a careful reassessment of the incentives to encourage additional organizations to provide funding

Variable resistance to Quambalaria pitereka in spotted gum reveal opportunities for disease screening

Quambalaria shoot blight, caused by the fungus Quambalaria pitereka, is a serious disease affecting the development of spotted gum (Corymbia citriodora subsp. citriodora, C. citriodora subsp. variegata, C. henryi and C. maculata) plantations in subtropical and tropical Australia. Incorporation of screening for resistance to Q. pitereka into current breeding programs is essential for the future development of plantations using spotted gum and Corymbia hybrids. The aim of this study was to determine whether there is variability in resistance among and within different species provenances and families of spotted gum to infection by Q. pitereka. A secondary aim was to consider whether the origin of seed source is a significant indicator of resistance to Q. pitereka. Assessments were conducted in trials consisting of spotted gum provenances, families and clones, all at the same site with high levels of disease pressure and with optimum climatic conditions for disease development. While all species and provenances of spotted gum could be infected by Q. pitereka, results showed that there are high levels of variability in resistance between and within species, provenances and families, indicating the potential to select for disease resistance. Provenance was shown to be an unreliable indicator of resistance to Q. pitereka