The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Nature and origin of tuff beds in Jurassic strata of the Surat Basin, Australia: implications on the evolution of the eastern margin of Gondwana during the Mesozoic

Volcanogenic rocks in the Great Australian Superbasin provide one of the principal records of contemporaneous volcanism in eastern Australia during the Mesozoic. However, the paucity of primary Jurassic to Early Cretaceous-age extrusive or intrusive igneous bodies on the Australian continent makes it particularly challenging to deduce their source and character. This, in turn, makes it difficult to ascertain how the eastern margin of Gondwana evolved during this timeframe. Despite some studies of this enigmatic volcanism, there have been little or no detailed analyses of these Jurassic to Early Cretaceous-aged sediments. Based on the multidisciplinary analyses of age-constrained air-fall tuffs (168 to 148 Ma) from the Jurassic Walloon Coal Measures of the Surat Basin, we suggest from zircon grains of a similar age that the tuffs were erupted from volcanoes fed by intermediate to felsic magmas supported by their quartz and feldspars-rich composition, and from zircon grains with low to moderate Nb values (0.5 to 100 ppm) and high U and Th values (30 to 1000 ppm). The mapping of tuff isopachs and a mean zircon crystal size of 170 μm supports the source being from volcanoes approximately 280 to 1000 km from the palaeoeast-southeast with a volcanic explosivity index (VEI) of 8. Our results indicate the tuffs originated from a continental arc setting associated with the Whitsunday Igneous Association, and the long-lived (late Palaeozoic to Cretaceous) westward subduction of the palaeo-Pacific oceanic crust beneath eastern Australia. Such a tectono-magmatic environment would help constrain the timing of the transition of eastern Gondwana from a convergent to a divergent margin.Carmine C. Wainman, Peter Reynolds, Tony Hall, Peter J. McCabe, Simon P. Holfor

Brachypodium distachyon Cell Suspension Cultures: Establishment and Utilisation

Brachypodium distachyon is emerging as the model species for temperate monocotyledonous grasses of the Pooideae, and the genome of the B. distachyon community inbred line Bd21 has recently been sequenced. Here, we report the development of a procedure for the efficient establishment of a cell suspension culture derived from calli. We show that embryogenic potential is maintained in 3-month-old cultures as the cells were positively labelled by the monoclonal antibody, JIM8 which recognizes a carbohydrate epitope often present in arabinogalactan proteins found in the cell walls of cells in embryogenic cultures. Additionally, we were able to regenerate plants from these cell suspension cultures. The cell suspension culture we have established can also be used in studies on plant programmed cell death (PCD). Our results clearly demonstrate that B. distachyon cells can undergo apoptosis-like PCD (AL-PCD) as visualised by the characteristic retraction of the protoplast from the cell wall. As B. distachyon is genetically related to important temperate cereal grass crops like wheat and barley, the ability to utilise cell suspension cultures of B. distachyon to dissect the underlying mechanisms PCD will have important implications for understanding developmental processes in economically important cereal crops

Saturated x-ray lasers at 196 and 73 Å pumped by a picosecond traveling-wave excitation

Traveling-wave irradiation with a laser pulse of duration ∼1 picosecond has been shown to achieve saturated operation of Ne- and Ni-like x-ray lasers. Gain at 196 Å was confirmed by observation of both forward and backward x-ray laser beams from a germanium plasma under ideal and nonideal traveling-wave conditions at a small signal gain of >40 cm-1. Saturation was observed for targets >4 mm long consistent with a model of laser amplification along the plasma medium and with the output of a detailed ray-tracing post-processor coupled to a hydrodynamic and atomic physics code. Ni-like samarium targets, pumped under ideal traveling-wave conditions exhibited a small signal gain of ∼19 cm-1 at 73 Å with saturation observed for targets 8 mm long

Rehabilitation implications during the development of the Norwich Enhanced Recovery Programme (NERP) for patients following total knee and total hip arthroplasty

SummaryBackground/hypothesisTo report the analysis of the initial rehabilitation results of the Norwich Enhanced Recovery Programme (NERP), regime with increased post-operative physiotherapy input following total hip arthroplasty (THA) and total knee arthroplasty (TKA) performed under spinal anaesthetic with wound catheter infiltration.Materials and methodsA secondary analysis of a service improvement programme was undertaken from an acute National Health Service Hospital in the United Kingdom. Ninety-five patients listed for THA (n=67) or TKA (n=28) were reviewed during the first six post-operative weeks. All received an enhanced post-operative programme including commencement of mobilisation four hours post-operatively and physiotherapy interventions a minimum of twice daily during hospital admission. The primary outcome measure was the Iowa Level of Assistance Score at discharge. Secondary outcomes included length of hospital stay (LOS), visual analogue scale pain at discharge and complications during the initial six post-operative weeks.ResultsThe NERP is a successful rehabilitation regime for patients following THA and TKA, facilitating early safe discharge (mean LOS=3.5 days) with minimal complications. Patients who commenced mobilisation on the day of the operation reported significantly reduced pain score (p=0.02) and length of stay (p<0.01) compared to those who did not. Thirty-four percent of patients were discharged with rollator frames.ConclusionsWhilst the early results of the NERP allow patients who have undergone THA or TKA surgery a short hospital length of stay, its demand on out-reach physiotherapy suggests that the availability of such community services is imperative to ensure the appropriate progression of rehabilitation.Level of evidenceLevel IV – retrospective series