Search for resonances in the mass distribution of jet pairs with one or two jets identified as b-jets in proton–proton collisions at √s=13TeV with the ATLAS detector

Searches for high-mass resonances in the dijet invariant mass spectrum with one or two jets identi-fied as b-jets are performed using an integrated luminosity of 3.2fb−1of proton–proton collisions with a centre-of-mass energy of √s=13TeVrecorded by the ATLAS detector at the Large Hadron Collider. Noevidence of anomalous phenomena is observed in the data, which are used to exclude, at 95%credibility level, excited b∗quarks with masses from 1.1TeVto 2.1TeVand leptophobic Z bosons with masses from 1.1TeVto 1.5TeV. Contributions of a Gaussian signal shape with effective cross sections ranging from approximately 0.4 to 0.001pb are also excluded in the mass range 1.5–5.0TeV

Phytogeographical analysis and checklist of the vascular plants of Loango National Park, Gabon

Background and aims - Floristic inventories are the primary means by which the plant diversity of an area can be understood and are important in underpinning management plans for conservation. One of the priorities set out for Loango National Park (LNP) in an IUCN assessment of Gabon's protected areas was to produce a vascular plant checklist. Therefore, the primary goal of this research was to significantly increase the number of specimens for the park and make a concentrated effort to increase knowledge of plant diversity in the area. The secondary goal of this study was to analyse the flora of LNP in terms of phytogeography and endemism. Methods - A specimen-based botanical inventory was carried out in LNP (1005 herbarium specimens collected for this study were added to 752 existing records) and vegetation observations were made. Phytogeographical analyses were also performed using two different methods and datasets for comparison. Key results - A preliminary checklist of 686 species of vascular plants of LNP is presented, making a significant contribution to our knowledge of the flora of Gabon with more than twenty new country records. Conclusions -There is a surprisingly high proportion (15%) of the overall Gabonese flora recorded from within the park in this preliminary checklist. Further inventory within the park will undoubtedly produce a much higher percentage of the flora of the whole country. This high proportion is explained in part by the combination of restricted coastal endemics, diversity of habitats, and dynamic biological and physical processes. Phytogeographical analyses reveal different floristic relationships between the forest and savanna components of the flora suggesting different origins of these two biomes in coastal Gabon. The forest species are typically Guineo-Congolian in distribution and the savanna species are Sudano- Zambezian or widespread in distribution. Together, the faunal elements and the high diversity of the flora of Loango National Park make it a globally important site for conservation

Constraining the timing and depositional conditions of the maikop formation within the Kura Basin, Eastern Azerbaijan, through the application of re‐os geochronology and chemostratigraphy

The Oligocene – Miocene Maikop Formation is the key source rock in the South Caspian and Kura Basins. The Maikop is composed of a thick (up to 3 km) succession of clay‐rich mudstones containing up to 15% total organic carbon (TOC). Despite decades of study, the mudstones often lack precise age control – Maikop strata rarely contain diagnostic microfaunal assemblages which can be used for dating, stratigraphic correlation, or constraining the depositional setting. Using rhenium‐osmium geochronology, this study adds important numerical age data for the Maikop Formation. Of five sample suites analysed from the Kura Basin, eastern Azerbaijan, one Re‐Os data‐set produced a significant range in 187Re/188Os versus 187Os/188Os space to yield an isochron of 17.2 ± 3.2 Ma (Early Miocene). Other sample suites yielded imprecise Re‐Os age constraints as a result of variable initial 187Os/188Os values and a limited range in 187Re/188Os versus 187Os/188Os space. The initial 187Os/188Os values of these data‐sets were compared with the known 187Os/188Os values of seawater for the past 70 Ma to provide more qualitative age constraints. Pre‐Maikopian strata from the Perikeshkul locality were found to coincide in 187Os/188Os values with an isotope excursion at the Eocene – Oligocene Transition (EOT), therefore indicating that deposition of Maikopian strata began around the EOT. While values such as this match well with global values, there are several 187Os/188Os values that are not easily explained by global ratios. Intervals with initial 187Os/188Os values that deviate significantly from global 187Os/188Os values suggest periodic basin restriction and the development of anoxia at discrete times as the basin transitioned towards a closed system. High Os abundances outside of expected global values are often coupled with enrichment in detrital elements (Al, Ti, Ga, Sc and La) and changes in basin circulation, suggesting changing basinal conditions and sediment routing dynamics related to the initial uplift of the Greater Caucasus Mountains, changes in sediment provenance, or changing proximity to the sediment source. Through generation of isochron age dates and imprecise Re‐Os age constraints from the Maikop Formation, we gain a better understanding of the timing and nature of the evolution of the South Caspian Basin during this critical time period. Better age constrains will also help to better constrain the wealth of geochemical information already gathered within this petroleum‐rich basin

Accumulation of manganese in Neisseria gonorrhoeae correlates with resistance to oxidative killing by superoxide anion and is independent of superoxide dismutase activity

As a facultative aerobe with a high iron requirement and a highly active aerobic respiratory chain, Neisseria gonorrhoeae requires defence systems to respond to toxic oxygen species such as superoxide. It has been shown that supplementation of media with 100 muM Mn(II) considerably enhanced the resistance of this bacterium to oxidative killing by superoxide. This protection was not associated with the superoxide dismutase enzymes of N. gonorrhoeae. In contrast to previous studies, which suggested that some strains of N. gonorrhoeae might not contain a superoxide dismutase, we identified a sodB gene by genome analysis and confirmed its presence in all strains examined by Southern blotting, but found no evidence for sodA or sodC. A sodB mutant showed very similar susceptibility to superoxide killing to that of wild-type cells, indicating that the Fe-dependent SOD B did not have a major role in resistance to oxidative killing under the conditions tested. The absence of a sodA gene indicated that the Mn-dependent protection against oxidative killing was independent of Mn-dependent SOD A. As a sodB mutant also showed Mn-dependent resistance to oxidative killing, then it is concluded that this resistance is independent of superoxide dismutase enzymes. Resistance to oxidative killing was correlated with accumulation of Mn(II) by the bacterium. We hypothesize that this bacterium uses Mn(II) as a chemical quenching agent in a similar way to the already established process in Lactobacillus plantarum. A search for putative Mn(II) uptake systems identified an ABC cassette-type system (MntABC) with a periplasmic-binding protein (MntC). An mntC mutant was shown to have lowered accumulation of Mn(II) and was also highly susceptible to oxidative killing, even in the presence of added Mn(II). Taken together, these data show that N. gonorrhoeae possesses a Mn(II) uptake system that is critical for resistance to oxidative stress