Optimization of experimental procedure for assessing transition metal ion FRET in LeuT

Neurotransmitter sodium symporters (NSSs) are important for the regulation of neurotransmitters, such as dopamine and serotonin, which are involved in addiction and depression, along with several other diseases. The bacterial NSS, LeuT, has been proven to be a good model protein for the mammalian NSSs. Conformational changes of LeuT can be examined using transition metal ion Fo ̈rster Energy Resonance Transfer (tmFRET), where the energy transfer between a fluorescien dye and a di-histidine bound Ni2+ is measured. When utilizing tmFRET, free Ni2+ is added to the solution, which also adds to the unspecific quenching signal detected. It is therefore necessary to remove the signal from the unbound Ni2+, in order to properly investigate the impact of specific bound Ni2+. Here we investigate whether the effect of Zn2+ can be used to inhibit FRET contribution from specifically bound Ni2+ and thereby isolate the non-specific signal. We found that Zn2+ can competitively inhibit the binding of Ni2+ to the di-histidine motif of LeuT, thereby representing an easier, and perhaps more consistent, method for removing the signal from unbound Ni2+ during tmFRET measurements

Newcastle Business School Principles of Responsible Management Education Project (NBS PRIME)

The world is changing rapidly and new demands face business leaders to deal with the planet and environment more sustainably, to deal with the numerous societies their organisations operate in more equitably and with greater cultural understanding, and to be more open, transparent and responsible with respect to their stakeholders. Recent events such as the credit and banking crisis alongside general global corporate social responsibility and sustainability concerns, have led to questions as to whether current management education is adequate to equip and develop future leaders with the requisite skills to meet these new demands (Colby, Ehrlich, Sullivan, Dolle, & Shulman, 2011; Datar, Garvin, & Cullen, 2010; Weybrecht, 2010). For these reasons it is essential that universities and business schools seek to embrace principles of sustainability and responsible management into their teaching, research and enterprise activities. Newcastle Business school is ideally placed to make a significant contribution to social, environmental and economic well being through its global reputation for delivering some of the best business management education in the UK

Scatter of mass changes estimates at basin scale for Greenland and Antarctica

During the last decade, the GRACE mission has provided valuable data for determining the mass changes of the Greenland and Antarctic ice sheets. Yet, discrepancies still exist in the published mass balance results, and comprehensive analyses on the sources of errors and discrepancies are lacking. Here, we present monthly mass changes together with trends derived from GRACE data at basin scale for both the Greenland and Antarctic ice sheets, and we assess the variability and errors for each of the possible sources of discrepancies, and we do this in an unprecedented systematic way, taking into account mass inference methods, data sets and background models. We find a very good agreement between the monthly mass change results derived from two independent methods, which represents a cross validation. For the monthly solutions, we find that most of the scatter is caused by the use of the two different data sets rather than the two different methods applied. Besides the well-known GIA trend uncertainty, we find that the geocenter motion and the recent de-aliasing corrections significantly impact the trends, with contributions of +13.2 Gt yr⁻¹ and −20 Gt yr⁻¹, respectively, for Antarctica, which is more affected by these than Greenland. We show differences between the use of release RL04 and the new RL05 and confirm a lower noise content in the new release. The overall scatter of the solutions well exceeds the uncertainties propagated from the data errors and the leakage (as done in the past); hence we calculate new sound total errors for the monthly solutions and the trends. We find that the scatter in the monthly solutions caused by applying different estimates of geocenter motion time series (degree-1 corrections) is significant – contributing with up to 40% of the total error. For the whole GRACE period (2003–2011) our trend estimate for Greenland is −234 ± 20 Gt yr⁻¹ and −83 ± 36 Gt yr⁻¹ for Antarctica (−111 ± 15 Gt yr⁻¹ in the western part). We also find a clear (with respect to our errors) increase of mass loss in the last four years

Improved retrieval of land ice topography from CryoSat-2 data and its impact for volume-change estimation of the Greenland Ice Sheet

A new methodology for retrieval of glacier and ice sheet elevations and elevation changes from CryoSat-2 data is presented. Surface elevations and elevation changes determined using this approach show significant improvements over ESA's publicly available CryoSat-2 elevation product (L2 Baseline-B). The results are compared to near-coincident airborne laser altimetry from NASA's Operation IceBridge and seasonal height amplitudes from the Ice, Cloud, and Elevation Satellite (ICESat). Applying this methodology to CryoSat-2 data collected in interferometric synthetic aperture mode (SIN) over the high-relief regions of the Greenland Ice Sheet we find an improvement in the root-mean-square error (RMSE) of 27 and 40 % compared to ESA's L2 product in the derived elevation and elevation changes, respectively. In the interior part of the ice sheet, where CryoSat-2 operates in low-resolution mode (LRM), we find an improvement in the RMSE of 68 and 55 % in the derived elevation and elevation changes, respectively. There is also an 86 % improvement in the magnitude of the seasonal amplitudes when compared to amplitudes derived from ICESat data. These results indicate that the new methodology provides improved tracking of the snow/ice surface with lower sensitivity to changes in near-surface dielectric properties. To demonstrate the utility of the new processing methodology we produce elevations, elevation changes, and total volume changes from CryoSat-2 data for the Greenland Ice Sheet during the period January 2011 to January 2015. We find that the Greenland Ice Sheet decreased in volume at a rate of 289 ± 20 km3a−1, with high interannual variability and spatial heterogeneity in rates of loss. This rate is 65 km3a−1 more negative than rates determined from ESA's L2 product, highlighting the importance of CryoSat-2 processing methodologies.</p