PI-200

We present results for the strange contribution to the electromagnetic form factors of the nucleon computed on the coordinated lattice simulation ensembles with N_{f}=2+1 flavors of O(a)-improved Wilson fermions and an O(a)-improved vector current. Several source-sink separations are investigated in order to estimate the excited-state contamination. We calculate the form factors on six ensembles with lattice spacings in the range of a=0.049-0.086 fm and pion masses in the range of m_{π}=200-360 MeV, which allows for a controlled chiral and continuum extrapolation. In the computation of the quark-disconnected contributions, we employ hierarchical probing as a variance-reduction technique.

The recovery of whale populations from centuries of exploitation will have important management and ecological implications due to greater exposure to anthropogenic activities and increasing prey consumption. Here, a Bayesian population model integrates catch data, estimates of abundance, and information on genetics and biology to assess the recovery of western South Atlantic (WSA) humpback whales (Megaptera novaeangliae). Modelling scenarios evaluated the sensitivity of model outputs resulting from the use of different data, different model assumptions and uncertainty in catch allocation and in accounting for whales killed but not landed. A long period of exploitation drove WSA humpback whales to the brink of extinction. They declined from nearly 27 000 (95% PI = 22 800-33 000) individuals in 1830 to only 450 (95% PI = 200-1400) whales in the mid-1950s. Protection led to a strong recovery and the current population is estimated to be at 93% (95% PI = 73-100%) of its pre-exploitation size. The recovery of WSA humpback whales may result in large removals of their primary prey, the Antarctic krill (Euphausia superba), and has the potential to modify the community structure in their feeding grounds. Continued monitoring is needed to understand how these whales will respond to modern threats and to climate-driven changes to their habitats.

The intricate mechanisms involved in the acquisition and translocation of polycyclic aromatic hydrocarbons (PAHs) in plants have not been elucidated. Phosphate (Pi) is the bioavailable form of essential macronutrient phosphorus, which is acquired and subsequently assimilated for plant optimal growth and development. Rice phosphate overaccumulator 2 (OsPHO2) is a central constituent of the regulation of Pi homeostasis in rice. In the present study, the role of OsPHO2 in regulating the translocation and accumulation of phenanthrene (Phe) and the involvement of Pi in this process were investigated. The temporal study (1 d-35 d) revealed a significant and gradual increase of Phe accumulation in Pi-deprived roots of wild-type (WT) seedlings. Compared with the WT, the concentrations of Phe were significantly higher in the shoots of ospho2 (OsPHO2 mutant) grown hydroponically with Phe (1.5 mg/L) under +Pi (200 μM) and -Pi (10 μM) conditions. The sap experiment clearly showed the significant increases in levels of Phe in the xylem sap of ospho2 than the WT grown hydroponically with Phe and +Pi. Further, the concentrations of both Phe and P were coordinately higher in the culms and flag leaves of the mutants than WT at maturity in potting soil with LPhe (6 mg/kg) and HPhe (60 mg/kg). However, the concentrations of Phe in the seeds were comparable in the WT and mutants, suggesting a pivotal of OsPHO2 in attenuating Phe toxicity in the seed. In +Phe WT, the relative expression level of OsPHO2 in the shoots was significantly lower, while those of Pi transporters (PTs) OsPT4 and OsPT8 were significantly higher in the roots compared with -Phe. Together, the results provided evidence towards the involvement of Pi in OsPHO2-regulated translocation and accumulation of Phe in rice.