Myths and legends of flowers, trees, fruits, and plants in all ages and in all climes,

"Second edition."

Electrical imaging and fluid modeling of convective fingering in a shallow water-table aquifer

Unstable density-driven flow can lead to enhanced solute transport in groundwater. Only recently has the complex fingering pattern associated with free convection been documented in field settings. Electrical resistivity (ER) tomography has been used to capture a snapshot of convective instabilities at a single point in time, but a thorough transient analysis is still lacking in the literature. We present the results of a 2 year experimental study at a shallow aquifer in the United Arab Emirates that was designed to specifically explore the transient nature of free convection. ER tomography data documented the presence of convective fingers following a significant rainfall event. We demonstrate that the complex fingering pattern had completely disappeared a year after the rainfall event. The observation is supported by an analysis of the aquifer halite budget and hydrodynamic modeling of the transient character of the fingering instabilities. Modeling results show that the transient dynamics of the gravitational instabilities (their initial development, infiltration into the underlying lower-density groundwater, and subsequent decay) are in agreement with the timing observed in the time-lapse ER measurements. All experimental observations and modeling results are consistent with the hypothesis that a dense brine that infiltrated into the aquifer from a surficial source was the cause of free convection at this site, and that the finite nature of the dense brine source and dispersive mixing led to the decay of instabilities with time. This study highlights the importance of the transience of free convection phenomena and suggests that these processes are more rapid than was previously understood.

Natural free convection in porous media: First field documentation in groundwater

Natural free convection is a process of great importance in disciplines from hydrology to meteorology, oceanography, planetary sciences, and economic geology, and for applications in carbon sequestration and nuclear waste disposal. It has been studied for over a century - but almost exclusively in theoretical and laboratory settings, Despite its importance, conclusive primary evidence of free convection in porous media does not currently exist in a natural field setting. Here, we present recent electrical resistivity measurements from a sabkha aquifer near Abu Dhabi, United Arab Emirates, where large density inversions exist. The geophysical images from this site provide, for the first time, compelling field evidence of fingering associated with natural free convection in groundwater.

Robert Graves

Robert Graves was a British writer who enlisted in August 1914. He fought at the Battle of Loos in 1915, and was wounded at the Somme in 1916. He published his first volumes of poems during the war, and his bestselling war memoir, Goodbye to All That, in 1929.

HES6 drives a critical AR transcriptional programme to induce castration-resistant prostate cancer through activation of an E2F1-mediated cell cycle network

Castrate-resistant prostate cancer (CRPC) is poorly characterized and heterogeneous and while the androgen receptor (AR) is of singular importance, other factors such as c-Myc and the E2F family also play a role in later stage disease. HES6 is a transcription co-factor associated with stem cell characteristics in neural tissue. Here we show that HES6 is up-regulated in aggressive human prostate cancer and drives castration-resistant tumour growth in the absence of ligand binding by enhancing the transcriptional activity of the AR, which is preferentially directed to a regulatory network enriched for transcription factors such as E2F1. In the clinical setting, we have uncovered a HES6-associated signature that predicts poor outcome in prostate cancer, which can be pharmacologically targeted by inhibition of PLK1 with restoration of sensitivity to castration. We have therefore shown for the first time the critical role of HES6 in the development of CRPC and identified its potential in patient-specific therapeutic strategies.

Baseline hypovitaminosis D is not associated with poor clinical outcomes in osteoarticular infections

OBJECTIVES Although vitamin D is recognized as an important factor in bone health, its role in osteoarticular infections is unclear. We hypothesized that low vitamin D (25-hydroxycholecalciferol) levels are associated with a lower likelihood of treatment success in osteoarticular infections. METHODS This was a retrospective cohort study of patients with orthopedic infections who had a 25-hydroxycholecalciferol level drawn when their infection was diagnosed. Outcomes were determined at early (3-6 months) and late (≥6 months) follow-up after completing intravenous antibiotics. RESULTS We included 223 patients seen during an 11-month period with osteoarticular infections and baseline 25-hydroxycholecalciferol levels. During the initial inpatient management of the infection, hypovitaminosis D was identified and treated. The mean 25-hydroxycholecalciferol level was 23±14ng/ml; 167 (75%) patients had levels <30ng/ml. Overall, infection treatment success was 91% (159/174) at early follow-up and 88% (145/164) at late follow-up. 25-Hydroxycholecalciferol baseline levels were similar in those with and without successful clinical outcomes, both at early (25±15 vs. 21±9ng/ml; p=0.3) and late follow-up (25±15 vs. 23±16ng/ml; p=0.6). CONCLUSIONS To our knowledge this is the first report on hypovitaminosis D and its impact on outcomes of osteoarticular infections. Hypovitaminosis D was frequent in this cohort. With vitamin D repletion, there was no difference in treatment success whether patients had baseline hypovitaminosis or not.