Dbp5p, a cytosolic RNA helicase, is required for poly(A)+ RNA export

The DBP5 gene encodes a putative RNA helicase of unknown function in the yeast Saccharomyces cerevisiae. It is shown here that Dbp5p is an ATP-dependent RNA helicase required for polyadenylated [poly(A)+] RNA export. Surprisingly, Dbp5p is present predominantly, if not exclusively, in the cytoplasm, and is highly enriched around the nuclear envelope. This observation raises the possibility that Dbp5p may play a role in unloading or remodeling messenger RNA particles (mRNPs) upon arrival in the cytoplasm and in coupling mRNP export and translation. The functions of Dbp5p are likely to be conserved, since its potential homologues can be found in a variety of eukaryotic cells.     

Nursing performance measures go public

Over 100 years ago, Florence Nightingale showed caregivers how to analyze mortality data to improve their clinical processes. The nurses of today are facing a new performance measurement challenge. Consumers of health care services want information that will help them compare quality among providers. This article describes the types of nursing performance measures most appropriate to include on these public-oriented report cards and several issues that influence report card design and dissemination.     

Alteration without change?: a commentary on the proposed policy reforms of the British National Health Service

Magnesium chloride (MgCl2) has been proposed for the treatment of seizures of different etiologies. The present study investigated the effect of MgCl2 on aldrin-induced seizures. Initially, 50 male rats received 60 mg aldrin/kg po and the effects were classified as muscular twitches, clonic convulsions or tonic-clonic convulsions. Another group of 40 rats dosed with 60 mg aldrin/kg po received 0, 4, 8, or 12 mg MgCl2/kg i.m. The percentage of tonic-clonic convulsant rats that resulted from MgCl2 treatment were 90% at 0 mg/kg, 50% at 4 mg/kg, 40% at 8 mg/kg and 20% at 12 mg MgCl2/kg. The percentage of survivors in the group receiving 12 mg MgCl2/kg was 80% while the control group had 20% survival. The clonic convulsions were not modified by MgCl2 treatment. Blood and brain concentrations of aldrin and dieldrin (metabolite of aldrin) did not differ among groups. The MgCl2 administration decreased the neuroexcitability induced by aldrin and increased survivability.     

Comparison of EEG and ECoG for detecting cerebrocortical activity during slaughter of calves

Parallel electrocorticograms (ECoG) and electroencephalograms (EEG) were recorded during stun-recovery and stun-slaughter of eight calves 4-6 weeks old. Epochs of 8·2 s duration, derived from the ECoG and EEG signals pre-stun, during recovery and during exsanguination, were compared for differences in power content and frequency distribution using Fast Fourier Transform analysis. ECoG signals recorded during the quiescent phase post-stun had a markedly lower power content compared with pre-stun, whereas the EEG signal showed no such reduction in power content. During exsanguination, the mean rate of decline in the ECoG power content was 0·025 log units/s, three times faster than the mean rate of decline of the EEG at 0·008 log units/s. The duration of the electroplectic fit post-stun was detected equally well by the two techniques. The differences between EEG and ECoG traces in this study are thought to arise from differences in the signal-noise ratio of the two techniques and by artefacts in the EEG signal, caused by microscopic movement between EEG electrodes and the surrounding tissue. The slower rate of decline in the power content of the EEG during slaughter means that the time to onset of isoelectric cortical electrical activity will be longer if determined by EEG measurements than by ECoG recording.     

Effect of steel microfibers on corrosion of steel reinforcing bars

Steel microfiber reinforcement was previously found to be successful in mitigating alkali silica reaction in concrete, an expansive phenomenon. The use of steel microfibers to mitigate rebar corrosion, another expansive reaction, was investigated. Mortar specimens with and without steel microfiber reinforcement were exposed to a corrosive environment. All specimens were prepared with water/cement ratios of both 0.40 and 0.55, cured for 28 days, and then submerged in aerated 3.5% NaCl solution. The corrosion behavior of the specimens was monitored via electrochemical measurements. Three types of electrochemical tests were performed: corrosion potential measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy. Chloride concentration measurements and microscopic analysis were performed as well. The polarization curves, Tafel, and polarization resistance measurements indicate that the steel rebar in the microfiber-reinforced mortars are more resistant to corrosion than the rebar in the control mortars, despite higher chloride concentrations. Furthermore, the steel microfiber-reinforced cement based materials have a lower electrolytic resistance. This is not indicative of a higher corrosion rate, which would be the case if it had been observed in standard mortar specimens.     

Activated gas plasma surface treatment of polymers for adhesive bonding

Polyethylene, polypropylene, poly(vinyl fluoride) (Tedlar), polystyrene, nylon 6, poly(ethylene terephthalate) (Mylar), polycarbonate, cellulose acetate butyrate, and a poly(oxymethylene) copolymer were treated with activated helium and with activated oxygen. Mechanical strengths of adhesive-bonded specimens prepared from treated and from untreated coupons were compared. Polyethylene (PE) and polypropylene (PP) showed the greatest increases in bond strength. Oxygen and helium were both effective with polyethylene, but polypropylene showed no improvement when treated with activated helium. The results with excited helium parallel the effects of ionizing radiation on these two polymers, as does the appearance of unsaturation bands in the infrared (965 cm^?1 in PE, and 887 and 910 cm^?1 in PP). Active nitrogen produced excellent bond strength with polyethylene but not with polypropylene. Of the remaining polymers examined, Tedlar, polystyrene, and nylon 6 showed the greatest improvement in bondability after treatment, and Mylar showed moderate improvement. Polycarbonate, cellulose acetate butyrate, and the poly(oxymethylene) copolymer gave approximately two-fold increases in lap-shear bond strength. In several cases, significant differences in response to time of treatment and type of excited gas were found.     

Intergranular and transgranular stress corrosion cracking of Cu---30Au

The mechanism of stress corrosion cracking (SCC) of Cu-30Au in 0.6 M NaCl was investigated by a series of experiments in which samples were de-alloyed by potentiostatic anodic polarization at 475 mV (Ag/AgCl) and at zero applied stress (i) for varying lengths of time (10 to 30 min) and then impact bent, and (ii) for 30 min followed by a period of time (5–30 s) at the open circuit potential and then impact bent, and (iii) for 30 min followed by anodic polarization at +150 mV (Ag/AgCl) for a period of time (5–30) and then impact bent. The results indicate that de-alloying at zero applied stress produces a surface layer that is capable for a brief period of time of inducing intergranular cleavage failure of the normally ductile substrate. In addition, samples were de-alloyed and simultaneously stressed at various nominal values (0.5–1.7 σ_y). At low values of stress, failure occurred by brittle intergranular cracking, and at high values of stress, failure occurred by brittle transgranular cracking. The results indicate that the electrochemical contribution to the SCC of Cu-30Au in 0.6 M NaCl is the same for both intergranular stress corrosion cracking (IGSCC) and transgranular stress corrosion cracking (TGSCC) and that the mode of fracture is dictated by the magnitude of the applied stress.     

The effect of electrical head-only stun duration on electroencephalographic-measured seizure and brain amino acid neurotransmitter release

Effective electrical head-only stunning produces a seizure-like state followed by a period of analgesia seen in animals allowed to recover. Passing of a 1·0 A current (50 Hz, 500 V) for less than 0·2 s, through the head of a sheep does not produce a seizure-like state as evidenced by recorded electroencephalogram. Corresponding to this lack of seizure-like state, the release of the neurotransmitters glutamate and aspartate, in the brain, occurs to levels associated with arousal rather than seizure. At a duration of 0·2 s, the same stun parameters as above produce a seizure-like state and the release of glutamate and aspartate rises dramatically. The length of the seizure-like state, and the levels of release of glutamate, aspartate and a third neurotransmitter gamma amino-4-butyric acid (GABA), increased with stun duration until 4·0 s duration, where a peak in these parameters was seen. Stun durations of 2·0, 4·0, 8·0 and 12·0 s all produce similar effects. At a duration of 20 s, however, the length of the seizure-like state and the release of neurotransmitters is less than at shorter stun durations. For welfare purposes a head-only electrical stun, of 1·0 A, at a duration as low as 0·2 s produces unconsciousness and analgesia to subsequent slaughter procedures. However, maximum welfare benefits appear attainable at durations between 2·0 and 20·0 s.     

Interpretation time of serial chest CT examinations with stacked-metaphor workstation versus film alternator

PURPOSE: Interpretation time of serial staging chest CT cases, which each contained current and previous examinations, with a simple prototype workstation called filmstack was experimentally compared with interpretation time with a film alternator. MATERIALS AND METHODS: The filmstack displayed a "stack" of sections for each examination; user controls allowed rapid selection of preset attenuation windows and both synchronized and unsynchronized scrolling. Eight radiologists were timed as they used the filmstack and the film alternator to interpret four ergonomically complex serial CT cases. RESULTS: All reports dictated on the basis of findings with filmstack and film were of acceptable clinical accuracy. The time to examine a case with filmstack was significantly faster than the time with film, including the time to load and unload the alternator (99% confidence [P = .01]). There was no statistically significant difference in interpretation time between filmstack and prehung film. CONCLUSION: Use of a low-cost stacked CT workstation with a single 1,024 x 1,024 monitor is an effective means of interpreting cases that require comparison of multiple CT examinations.