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The long-time limit of the response of incompressible three-dimensional boundary layer flows on infinite swept wedges and infinite swept wings to impulsive forcing is examined using causal linear stability theory. Following the discovery by Lingwood (1995) of the presence of absolute instabilities caused by pinch points occurring in the radial direction in the boundary layer flow of a rotating disk, we search for pinch points in the cross flow direction for both the model Falkner–Skan–Cooke profile of a swept wedge and for a genuine swept-wing configuration. It is shown in both cases that, within a particular range of the parameter space, the boundary layer does indeed support pinch points in the wavenumber plane corresponding to the crossflow direction. These crossflow-induced pinch points do not constitute an absolute instability, as there is no simultaneous pinch occurring in the streamwise wavenumber plane, but nevertheless we show here how they can be used to find the maximum local growth rate contained in a wavepacket travelling in any given direction. Lingwood (1997) also found pinch points in the chordwise wavenumber plane in the boundary layer of the leading-edge region of a swept wing (i.e. at very high flow angles). The results presented in this paper, however, demonstrate the presence of pinch points for a much larger range of flow angles and pressure gradients than was found by Lingwood, and indeed describe the flow over a much greater, and practically significant, portion of the wing.

A prism spectrum of PSR B0540-69, the 50 ms pulsar in the Large Magellanic Cloud, was obtained with the Faint Object Spectrograph on the Hubble Space Telescope. This is only the second pulsar spectrum that has been observed in the optical. The 2500-5500 A spectrum shows a smooth continuum with several broad emission lines. The lines are emitted by the extended nebula surrounding B0540-69. Less than 30% of the total flux in the spectrum can be contributed by the synchrotron nebula surrounding the pulsar; the time-averaged emission from the pulsar must be the dominant source of the continuum. The observed spectral index, α, of the continuum, where flux density Sν = Kνα μJy, is -2.5 ± 0.2 between 2500 and 4500 A. Using E(B - V) = 0.20 ± 0.05 gives a de-extincted spectral index α0 = -1.6 ± 0.4. This intrinsic spectral index is significantly different from that of the Crab pulsar in the optical α0 = 0.11 ± 0.13. Unless E(B - V) ~ 0.5, the intrinsic spectral index of time-averaged pulsar radiation must vary as much from pulsar to pulsar in the high-frequency regime as it does in the radio.

The foraging behaviour of sub-adult Nucella lapillus originating from different field populations, was monitored for ten alternating, biweekly, periods of calm and wave action simulated in a tidal aquarium. Because the dogwhelks were reared under standard laboratory conditions, any behavioural differences among the experimental populations could reasonably be inferred to be linked to some genetically based mechanism. In order to forage, the dogwhelks had to leave a refugium, traverse empty 'habitat' and enter a patch of mussels serving as prey. Wave action markedly depressed foraging activity, increased foraging latency and lowered the patch-residence-time index. Dogwhelks derived from populations naturally occurring on shores exposed to wave action reduced their foraging activity less strongly than those derived from sheltered-shore populations, but geographical origin (Plymouth or Anglesey) had no significant influence on foraging behaviour. A simple interpretation was offered, linking the differential behavioural response to habitat-specific shell morphology, known to be heritable. According to this interpretation, all dogwhelks react similarly to the drag forces generated by wave action, but the relatively shorter-spired shells of exposed-shore dogwhelks cause weaker resultant forces than the taller-spired shells of sheltered-shore individuals. Consequently, exposed-shore dogwhelks tolerate higher levels of wave action than sheltered-shore morphs before suppressing their foraging behaviour. As exposed-shore dogwhelks have greater tenacity associated with relatively larger pedal area, the increased tolerance of wave action extends opportunities for foraging without incurring extra risk of dislodgement. The sheltered-shore morphology, which imparts greater resistance to desiccation, coincidentally increases drag and so makes dogwhelks more likely to seek refuge during occasional periods of heavy wave action. Exposed- and sheltered-shore morphologies therefore represent genotype/environment interaction that is apparently adaptive, in part, through its effect on foraging behaviour.

The gastric emptying of pellets and single units of different densities has been followed in healthy subjects using the technique of gamma scintigraphy. The gastric emptying of the light pellets was affected by their buoyancy in the upper part of the stomach. However, the mean gastric emptying rates of pellets and single units were not significantly affected by density. Floating or buoyant delivery systems may have little advantage over conventional systems. The presence of food in the stomach was found to be the major factor in determining the gastric emptying of single units.

We report the first polarimetric observations in the ultraviolet of two AGN's, the blazar BL Lac and the gravitational lens candidate Q2345+007. We find strong (p>3%) and variable UV polarization in BL Lac, two of the characteristics exhibited by blazars in the visible. The polarization of BL Lac in the UV decreased significantly (from 18% to

Objective : Recently, transesophageal echocardiography (TEE) has been proposed as the standard for the diagnosis of traumatic disruption of the aorta (TDA), replacing aortography. The purpose of this study was to evaluate the accuracy and practicality of TEE in the diagnosis of TDA. Design : Prospective clinical trial. Materials and Methods : Patients with blunt trauma admitted with a suspected diagnosis of TDA were evaluated with TEE and aortography. Measurements and Main Results : Thirty-four patients were evaluated with TEE and aortography. TEE was unsuccessful in five patients (15%). Of the remaining 29 patients, TEE results were true-positive in four and true-negative in 20. TEE results were false-positive in two patients, and three injuries were missed (two were proximal to the left subclavian artery, and one was a localized aortic disruption). Sensitivity and specificity of TEE were 57% and 91%, respectively, compared with aortography, for which sensitivity was 89% and specificity was 100%. Conclusion : Although the use of TEE in the diagnosis of TDA has several advantages, it is not more accurate than aortography. TEE should not replace aortography as the standard for the diagnosis of TDA.

Molecular modeling using structure elucidation programs in conjunction with molecular simulation programs has been performed on asphaltene molecules, the heaviest fraction of crude oil, in order to obtain a chemical model allowing us to tentatively study their physicochemical properties. We have analyzed Boscan asphaltenes (Venezuela) derived from a marine source rock. The different steps of this molecular modeling are described. First, a 3-D chemical representation of Boscan asphaltene is defined from an analytical data set. Second, the results of molecular dynamic simulations indicate that only a few stable conformations are possible due to the high reticulation of the model of the asphaltene unit obtained.

Background Regulators have issued warnings about the potential adverse effects of the smoking cessation medication varenicline. However, there is little evidence of the long-term effects of varenicline when prescribed in everyday clinical practice. We aimed to investigate the association of varenicline and nicotine replacement therapy (NRT) with adverse outcomes when prescribed in primary care. Methods Using the Clinical Practice Research Datalink (CPRD), we conducted an observational cohort study of electronic medical records and linked mortality and hospital admission data of 126 718 primary care patients in the UK prescribed varenicline (41 742) and NRT (84 976). We used three approaches to overcome potential residual confounding: multivariable adjusted regression, propensity score matching, and instrumental variable regression. The exposure was first prescription of varenicline or nicotine replacement therapy. The primary outcome was all-cause mortality 2 years after first prescription. Secondary outcomes were mortality from cardiovascular and respiratory disease, all-cause hospital admission and for cardiovascular and respiratory disease, incident primary care diagnosis of myocardial infarction or chronic obstructive pulmonary disease, and frequency of primary care attendance. Findings In multivariable adjusted analysis, mortality was lower among patients prescribed varenicline than in those prescribed NRT (OR 0·78, 95% CI 0·69 to 0·87; p Interpretation There was little evidence of a substantial increase in risk of adverse outcomes in patients prescribed varenicline as part of their standard clinical care. The regulatory warnings associated with varenicline do not accurately reflect the scientific evidence and should be reconsidered by policy makers and regulators. Funding The research described in this paper was funded by the Medical Research Council (MR/N01006X/1), the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme (project number 14/49/94). KHT is funded by a clinical lectureship award from the NIHR. RMM is supported by Cancer Research UK (programme grant C18281/A19169) (the Integrative Cancer Epidemiology Programme). TJ is supported by the NIHR Collaboration for Leadership in Applied Health Research and Care West, University Hospitals Bristol NHS Foundation Trust. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; or preparation, review, or approval of the abstract for submission.

Corneal cryopreservation requires that endothelial cells remain viable and intercellular structure be preserved. High viability levels for cryopreserved endothelial cells have been achieved, but preserving intercellular structure, especially endothelial attachment to Descemet's membrane, has proved difficult. Cell detachment apparently is not caused by ice, suggesting osmotic or chemical mechanisms. Knowledge of the permeation kinetics of cryoprotectants (CPAs) into endothelial cells and stroma is essential for controlling osmotic and chemical activity and achieving adequate tissue permeation prior to cooling. Proton nuclear magnetic resonance (NMR) spectroscopy was used to assess the permeation of dimethyl sulfoxide (DMSO) into isolated rabbit corneas. Corneas with intact epithelia were exposed to isotonic medium or 2.0 mol/L DMSO for 60 min and subsequently transferred to 2.0 or 4.0 mol/L DMSO, respectively, at 22, 0, or -10 degrees C. DMSO concentration in the cornea was measured vs time. The Kedem-Katchalsky model was fitted to the data. Hydraulic permeability (m3/N.s) is 7.1 x 10(-13) + 216%-11% at 22 degrees C, 8.2 x 10(-13) + 235%-21% at 0 degree C, and 1.7 x 10(-14) + 19%-16% at -10 degrees C. The reflection coefficient is 1.0 + 2%-1% at 22 degrees C and 0 degree C, and 0.9 +/- 5% at -10 degrees C. Solute mobility (cm/s) is 5.9 x 10(-6) + 6%-11% at 22 degrees C, 3.1 x 10(-6) + 12%-11% at 0 degree C, and 5.0 x 10(-8) cm/s + 59%-40% at -10 degrees C.

A simplified version of the specific contact resistance measurement scheme of G. K. Reeves [Solid State Electronics 23, 487 (1980)] has been developed. Its applicability to semiconducting diamond is demonstrated using four sample types: epitaxial films doped to mid 1019 acceptors/cm3 on 〈100〉 and 〈110〉 type IIa substrates; type IIb diamonds 0.25 mm thick, and type IIb diamonds thinned to 0.035–0.05 mm thick. The ohmic contacts were based on a solid‐state annealing process using carbide forming metals. The measured specific contact resistance depends mainly on the doping level in the diamond. Measured values ranged from 8×10−6 Ω cm2 for heavily doped films to 1×10−2 Ω cm2 for lightly doped bulk samples. A simple analysis shows that the contacts to highly doped layers are suitable for device applications.

Background The benefits of hypothermia for preventing ischemic injury are well known, but its application in surgery to protect the whole body during procedures requiring circulatory arrest is currently limited to Methods and Results With the use of extracorporeal cardiac bypass, 14 adult dogs were exsanguinated during cooling; 11 dogs were blood substituted using in combination the “purge” and “maintenance” solutions (group 1), and 3 dogs were perfused throughout with the “purge” solution alone as controls (group 2). After cardiac arrest, the solutions were continuously circulated for 3 \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{1}{2}\) \end{document} hours by the extracorporeal pump (flow rate, 40 to 85 mL · kg −1 · min −1 ; mean arterial blood pressure, 25 to 40 mm Hg). The temperature was maintained at P P P =.03), and for CK-BB, the group 1 value was 108±22 versus 617±154 for group 2 ( P =.03). Neurological evaluation using deficit scores (NDS) was based on a modification of the Glasgow Coma Scale score: 0, normal; 1, minimal abnormality; 2, weakness; 3, paralysis; 4, coma; and 5, death. At days 1 and 2 after surgery, NDS (mean±SEM) were 0±0 for the experimental group versus 1.5±0.5 for the control group. At days 3 and 7 after surgery, NDS were 0±0 for group 1 versus 1.0±1.0 for group 2. Conclusions The faster neurological recovery of dogs treated with the “intracellular-type” maintenance solution supports the biochemical data showing the benefits of this type of blood substitute for extending the safe limits of hypothermic cardiac arrest procedures to >3 hours.

A self regulating delivery device, responsive to glucose, has been shown to operate successfully in vitro. This comprises a gel membrane which determines the delivery rate of insulin from a reservoir. The gel consists of a synthetic polysucrose and the lectin, concanavalin A. The mechanism is one of displacement of the branched polysaccharide from the lectin receptors by incoming glucose. The gel loses its high viscosity as a result but reforms on removal of glucose, thus providing the switch controlling the drug diffusion rate. The drug does not require to be chemically modified and thus the device is adaptable to other anti-hyperglycaemic drugs. However, results here indicate that the molecular weight of the solute may be an important parameter. Others include path length, gel formulation and temperature. It had been hypothesised that the reversal might be improved by the use of a non-aqueous reservoir of insulin. However, with the use of insulin, the switching off was found to be superior to that found with other test solutes used in previous studies, irrespective of the reservoir solvent. The advantages in the use of the non-aqueous system include, however, more reproducibility in the magnitude of response and a reduced temperature sensitivity.

The Recoil‐Distance Doppler‐shift method has been combined with Recoil‐Decay Tagging for the first time to measure a lifetime in the proton‐unbound nucleus 109I. The lifetime value was determined using the Differential Decay‐Curve method in singles mode. The result has been compared to theoretical shell‐model calculations in order to better understand the nature of unbound valence nucleons at the proton drip line.

Paspalum-dominant pastures suffer from poor winter/spring herbage production, which can be corrected by direct-drilling cool-season-active species such as ryegrass. The growth and persistence of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) direct-drilled into a paspalum (Paspalum dilatatum Poir.)-dominant, rotationally grazed dairy pasture, and their effects on production, were studied over 5 years. Treatments were original pasture (control) and herbicide treatment with 0, 0.72, 1.44, and 2.16 kg a.i./ha of glyphosate (Roundup® herbicide, 36% glyphosate) before direct-drilling. Observations on tagged ryegrass and white clover plants found establishment plant numbers for ryegrass were 74% higher (788 plants/m2) in herbicide-treated than in untreated areas (452 plants/m2). Half of all tagged ryegrass plants disappeared in the first year after which losses were much reduced. The establishment and survival of tagged white clover plants were poor. Paspalum gradually re...

This paper discusses the results of a local initiative in the West Midlands (UK) which looked at how businesses in engineering, utilities and foundry trades managed the risks from hand-arm vibration. Inadequacies of health surveillance programmes and the need for enforcement action are outlined.

Objectives: This is a cross-sectional, observational study to determine the frequency and associated features of HIV-associated neurocognitive disorders (HAND) in a large, diverse sample of infected individuals in the era of combination antiretroviral therapy (CART). Methods: A total of 1,555 HIV-infected adults were recruited from 6 university clinics across the United States, with minimal exclusions. We used standardized neuromedical, psychiatric, and neuropsychological (NP) examinations, and recently published criteria for diagnosing HAND and classifying 3 levels of comorbidity (minimal to severe non-HIV risks for NP impairment). Results: Fifty-two percent of the total sample had NP impairment, with higher rates in groups with greater comorbidity burden (40%, 59%, and 83%). Prevalence estimates for specific HAND diagnoses (excluding severely confounded cases) were 33% for asymptomatic neurocognitive impairment, 12% for mild neurocognitive disorder, and only 2% for HIV-associated dementia (HAD). Among participants with minimal comorbidities (n = 843), history of low nadir CD4 was a strong predictor of impairment, and the lowest impairment rate on CART occurred in the subset with suppressed plasma viral loads and nadir CD4 ≥200 cells/mm3(30% vs 47% in remaining subgroups). Conclusions: The most severe HAND diagnosis (HAD) was rare, but milder forms of impairment remained common, even among those receiving CART who had minimal comorbidities. Future studies should clarify whether early disease events (e.g., profound CD4 decline) may trigger chronic CNS changes, and whether early CART prevents or reverses these changes. © 2010 by AAN Enterprises, Inc. All rights reserved.

Quinuclidines with a 3-biaryl substituent are a new class of potent, orally active squalene synthase (SQS) inhibitors. Variants around these rigid structures indicate key structural requirements for cationic SQS inhibitors. Thus the lower in vitro potency found for quinuclidines bearing 3-substituents, which did not overlay the biphenyl group of 3-(biphenyl-4-yl)-3-hydroxyquinuclidine (2) (IC50 = 16 nM, rat microsomal SQS), implied a directional requirement for the 3-substituent. Similarly, the lower potency of the 3-terphenyl analogue 6 (IC50 = 370 nM) indicated size constraints for this substituent. In compounds with a linking group between the quinuclidine and biphenyl ring, linking groups of lower lipophilicity were less well tolerated (e.g., 17, CH2CH2, IC50 = 5 nM vs 19, NHCO, IC50 = 1.2 μM). Replacement of the distal phenyl ring of 2 with a more polar pyridine heterocycle caused a reduction in in vitro potency. In general, good in vivo activity in the rat was restricted to 3-hydroxy analogues, with...

A compact laser rangefinder has been developed, which incorporates a sealed-off pulsed CO(2) TEA laser and uses direct (i.e., nonheterodyne) detection. This device is essentially eye safe and benefits from the superior atmospheric transmission at 10.6-microm wavelength. Design parameters are presented and illustrated, and system performance is discussed.

The orientation of the valine-1 side chain of gramicidin was determined by solid-state 2H NMR using valine-1-deuterated (d8) gramicidin. The peptide was incorporated into DMPC bilayers that were oriented between glass plates. When the plates were oriented with their normal perpendicular to the magnetic field, four quadrupolar splittings were observed of 106, 68, 9.7, and 2.0 kHz. These resonances were assigned to C alpha D, C beta D, and the deuterons of each of the C gamma D3 methyl groups, respectively. The average orientation of the various C-D bonds was calculated with respect to the helix axis. The angle obtained for the C alpha-D resonance was consistent with a single-stranded beta 6.3-helical model for the backbone but not with double-helical models. The angles of the side chain were then fitted to a model for the right-handed beta 6.3-helix. Rotation of the valine-1 side chain yielded a set of torsion angles that matched the angles as determined from the 2H NMR measurements. The corresponding orientation of the valine-1 side chain (chi 1 = -5 degrees) was found to be quite unusual, but it explains well the importance of a branched side chain at position 1 for channel formation and stability. A van der Waals interaction between valine-1 of one monomer and alanine-5 of the other helps to stabilize the gramicidin dimer.

Four glasshouse experiments and two field trials were conducted to determine the effects of perennial ryegrass (Lolium perenne L.) infected with Acremonium lolii Latch, Christensen & Samuels on white clover (Trifolium repens L.) germination, emergence, growth, and survival. Under controlled laboratory experiments, ryegrass leachates temporarily inhibited the rate of white clover germination, but did not affect white clover emergence or yield. In glasshouse experiments, the presence of A. lolii did not influence white clover emergence or growth. Emergence of indicator plant species grown in pumice sand substrate which previously grew ‘Ellett’ or ‘Grasslands Nui’ perennial ryegrass was not affected (‘Ellett’) or was enhanced (‘Grasslands Nui’) by the presence of A. lolii. In field trials, A. lolii infection did not significantly affect white clover survival, vigour, or leaves and stolons per plant, when ryegrass tiller densities were similar. Later, when tiller density of A. lolii-free plants decre...

A critical review of techniques used in the assessment of microleakage in dental restorations is presented. These techniques include the use of air pressure, bacteria, radioisotopes, electrochemistry, chemical tracers and dye penetration. Wide variations in methodologies are revealed.

Purified peripheral blood polymorphonuclear leucocytes (PMNs) from patients with rheumatoid arthritis (RA) have been found to differ from purified PMNs from normal subjects in ways that are consistent with their prior activation. However, it is currently contentious whether activated PMNs really circulate in patients with RA, or whether they are produced as an in vitro artefact of purification. Recently developed rapid leucocyte fixation and preparation technique showed that the proportion of polarised (activated) PMNs (36.9 (24.7)%, mean (SD); n = 31) was increased relative to that in control subjects (8.1 (5.6)%; n = 12). Serum cytidine deaminase levels, a biochemical marker of PMN lysis, were also increased in patients with RA (11.59 (7.26) U/ml) compared with those in controls (6.82 (3.78) U/ml), but the proportion of polarised PMNs and the levels of cytidine deaminase activity were unrelated to clinical assessments of inflammatory disease activity. Twelve patients who were not receiving drugs or who were receiving only non-steroidal anti-inflammatory drugs (NSAIDs) had more polarised PMNs than 19 patients receiving second line treatment in addition to NSAIDs (patients receiving NSAIDs, 49.6 (25.9)%; patients receiving second line treatment, 27.5 (21.1)%). Fluorescence activated cytometric analysis of CR1 and CR3 expression on PMNs from a randomly selected subgroup of patients with RA showed that the serum level of cytidine deaminase activity was correlated positively with the expression of CR1 (the C3b receptor) on the cell surface and that the proportion of polarised PMNs was positively correlated with the expression of CR3 (or CD11b/CD18), the iC3b receptor that is upregulated on activation. It is suggested that the polarised PMNs which circulate in blood samples from patients with RA represent cells which have been activated but not yet marginated, or activated cells which have marginated but subsequently returned to the circulating pool.

Field desorption - mass spectrometry (FD-MS) was evaluated as a tool for characterisation of the complex mixtures of compounds typical of synthetic lubricants. The lubricants were initially screened using field ionisation, then tested samples were subjected to field desorption. Results are presented for various formulations for an ester, an ester-synthetic oil mixture, polyisobutylenes, PAO additives, and a fully formulated oil.

This study explores the behavior of a flat-slab, sensible heat thermal energy storage system, the physical design and operation of which have been optimized to minimize the production of entropy by thermodynamic irreversibilities. Unlike many previous studies, the present work includes the entropy production by transient heat conduction within the storage element; that is, the analytical model is based on a distributed, as opposed to a lumped, storage element. The work is presented in two parts. The development of the analytical model required to compute the figure of merit, which is called the entropy generation number, in terms of the design and operational parameters of the system is presented in Part I. In Part II, the numerical solution of the analytical model is discussed and the results of an optimization study are presented and interpreted.

This study explores the behavior of a flat-slab, sensible heat thermal energy storage system, the physical design and operation of which have been optimized to minimize the production of entropy by thermodynamic irreversibilities. The analytical model is developed in Part I of this work. This part includes a description of the numerical model and the presentation and interpretation of the results of a system optimization study. The major results of this study show that: 1) any Second Law model of a thermal energy storage system must include a distributed storage element in order to make realistic estimates the thermodynamic performance of the system; 2) unconstrained optimization of the design of a thermal energy storage system tends to yield a system that is undesirably large, but by constraining the number of transfer units (NTU), it is possible to design systems of a realistic size without seriously degrading the thermodynamic performance; 3) counterflow systems operated without a dwell period are the most efficient type of system; and 4) the use of a dwell period with a counterflow system, or the operation of a system in parallel flow instead of counterflow, degrades the thermodynamic performance of the system and increases the required system size (NTU) in comparison to a counterflow system operated without a dwell period.

Two reservoir cores and one synthetic alumina sample have been quantitatively studied by means of proton, spin-lattice relaxation of the bulk samples, and by 2D-FT slice selected imaging. T1 and M0 images of high quality have been obtained with reasonable data acquisition and data processing times. T1 and T2 relaxation processes have been shown to be correlated, and possible causes for the differences between average image T1 values and those measures for the bulk samples are discussed. Variation of T1 within the images is discussed in terms of the contributions from pore size and surface relaxation effects.

A 5-year experiment at Ruakura Agricultural Centre measured the effects of blanket application of glyphosate herbicideand direct drilling ofperennial ryegrass and white clover on seasonal pasture composition and production. Plots were sprayed in autumn 1985 with 6,4,2 and 0 l/ha of glyphosate before direct drilling with a mixture of 'Ellett' ryegrass and 'Grasslands Kopu' white clover. These treatments werecompared with plots of the original paspalum pasture which was not sprayed or drilled. Plots were arranged at random in 6 replicate blocks that were rotationally grazed by dairy cows. Applying high rates (4-6 l/ha) of glyphosate completely eliminated paspalum from the pasture and subsequently, treatment differences between the 6 and 4 l/ha treatments for most variables were small. Differences in winter/spring herbage accumulation between the 4 l/ha treatment and the control plots were highest in the first year and declined with time, representing 1.9,0.8,0.8.0.6 and 0.4 t DM/ha, respectively, over the S years of the trial. The declining growth response was paralleled by an increasing level of paspalum in the previously sprayed plots, which exceeded 30% of DM by the fourth summer. Over the same period, their summer ryegrass contents had declined by more than half (46-20% of DM). These results suggest that for this site further renovation using glyphosate (at 4 l/ha) would be beneficial after 4 years to recapture the immediate superior growth responses, and since the costs of renovation could be met within 2 years. Keywords Paspalum dilitatum, Lolium perenne, seasonal herbage accumulation, renovation methods, glyphosate herbicide, dairy pastures, volunteer paspalum invasion, pasture botanical composition stability

A number of streptavidin-linked reporter molecules at the endpoint of a five-step detection protocol for viral in situ hybridization using biotinylated probes were examined. DNA-DNA and RNA-RNA model systems were used. Streptavidin linked to either peroxidase or fluorescein was found to be optimal in terms of sensitivity and resolution within individual cells. All other reporter molecules labelled similar numbers of cells with low background reaction. However, streptavidin-5 nm gold followed by silver enhancement gave very high background staining making interpretation of positive signals very difficult.

Multicolor discrimination is one of the most effective ways of improving the performance of infrared missile warning sensors, particularly for heavy clutter situations. A new tactical airborne multicolor missile warning testbed was developed and fielded as part of a continuing Air Force Research Laboratory (AFRL) initiative focusing on clutter and missile signature measurements for effective missile warning algorithms. The developed sensor test bed is a multi-camera system 1004x1004 FPA coupled with optimized spectral filters integrated with the optics; a reduced form factor microprocessor-based video data recording system operating at 48 Hz; and a real time field programmable gate array processor for algorithm and video data processing capable of 800B Multiply/Accumulates operations per second. A detailed radiometric calibration procedure was developed to overcome severe photon-limited operating conditions due to the sub-nanometer bandwidth of the spectral filters. This configuration allows the collection and real-time processing of temporally correlated, radiometrically calibrated video data in multiple spectral bands. The testbed was utilized to collect false alarm sources spectra and Man-Portable Air Defense System (MANPADS) signatures under a variety of atmospheric and solar illuminating conditions. Signatures of approximately 100 missiles have been recorded.

Effective missile warning and countermeasures remain an unfulfilled goal for the Air Force and others in the DOD community. To make the expectations a reality, newer sensors exhibiting the required sensitivity, field of regard, and spatial resolution are being developed and transitioned. The largest concern is in the first stage of a missile warning system: detection, in which all targets need to be detected with a high confidence and with very few false alarms. Typical fielded sensors are limited in their detection capability by either lack of sensitivity or by the presence of heavy background clutter, sun glints, and inherent sensor noise. Many threat environments include false alarm sources like burning fuels, flares, exploding ordinance, arc welders, and industrial emitters. Multicolor discrimination has been shown as one of the effective ways to improve the performance of missile warning sensors, particularly for heavy clutter situations. Its utility has been demonstrated in multiple demonstration and fielded systems. New exploitations of background and clutter spectral contents, coupled with advanced spatial and temporal filtering techniques, have resulted in a need to have a new baseline algorithm on which future processing advances may be judged against. This paper describes the AFRL Suite IIIc algorithm chain and its performance against long-range dim targets in clutter.

Gamma decays have been observed for the first time in the Tz = −3/2 nucleus 53Ni. This represents the first gamma‐spectroscopy of a Tz = −3/2 nucleus heavier than A = 33. The nucleus was produced via a two‐step fragmentation process, along with its mirror 53Mn. Differences in excitation energy between isobaric analogue states have been calculated and a preliminary interpretation attempted; shell model calculations are required to further understand these results. This work represents the first study of isobaric analogue states via mirrored fragmentation reactions and demonstrates the power of this new technique.

Techniques have been developed to produce ohmic contacts to naturally occurring boron doped semiconducting diamond. Thin films of Mo, Mo/Au, and Mo/Ni/Au deposited on diamond produced adherent ohmic contacts after annealing at 950 °C. A thermally activated solid state reaction which produces a refractory carbide precipitate at the original diamond/metal interface is the principal factor in affecting the properties of the contacts. The interface reaction has been characterized using Auger electron spectroscopy, scanning electron microscopy, x‐ray diffraction, metallography, and I‐V measurements.

Field-desorption mass spectrometry has been used to characterize polystyrene oligomers of molecular weight up to 15 000 Da. The technique shows good agreement with molecular weight data calculated using vapour-phase osmometry and gel-permeation chromatography but in addition provides much more detailed information in terms of oligomer distribution and the nature of end groups present in the oligomers.

Optimised immunocytochemical (ICC) and in situ hybridisation (ISH) protocols for long term, formalin fixed, central nervous system tissue infected with measles virus were developed. The effectiveness of 10 proteases for the enzymatic unmasking of formalin fixed antigen and nucleic acid was investigated. Protease VIII gave maximal signal generation with optimal tissue preservation and no background staining for both techniques. The use of a microwave oven as an additional pre-hybridisation step for RNA-RNA in situ hybridisation produced a significant increase in the number of cells labelled for genomic RNA. The ability to show the presence of antigen and nucleic acid in long term, formalin fixed tissue facilitates the use of stored necropsy material available in pathology departments for ICC and ISH investigations.

The 1H NMR laboratory- and rotating-frame (LF,RF) spin-lattice relaxation (SLR) behaviour in solid polyethylenes is reviewed in light of the two region spin diffusion coupled model. Highly crystalline high-density materials show single T1 values indicative of the fast diffusion limit whilst RFSLR is close to the slow diffusion limit, allowing direct determination of the dimensions of the crystalline and disordered regions. The LFSLR and RFSLR of the HDPE's suggest the existence of an interfacial material which the SLR behaviour includes as part of the crystalline region in contrast to XRD and DSC. 13C CPMAS measurements of 1H RFSLR in a LLDPE provide an additional insight into this problem. The 1H RFSLR is best represented by a superposition of two exponentials, measured by either 1H or 13C NMR. The 1H RFSLR, measured at different chemical shifts in the 13C NMR spectrum, provides direct evidence of the interfacial material. The possible use of spin-locking at angles other than 90° in the rotating frame to scale the spin diffusion rates is reviewed and its possible utility for LLDPE materials explored.

Summary An anaesthetised 48-year-old woman became haemodynamically unstable following biopsy of a thoracic mass suggesting a diagnosis of a thoracic phaeochromocytoma. Surgery was postponed to allow confirmatory investigations and pre-operative adrenoceptor blockade with phenoxybenzamine and labetalol. Nine days later, following resection of her phaeochromocytoma, she suffered an intra-operative asystolic cardiac arrest which was unresponsive to standard resuscitation protocols and required external cardiac pacing. We discuss the issues involved and suggest that the competitive α1 adrenoceptor antagonist doxazosin may be preferable to the covalently bound mixed alpha adrenoceptor antagonist phenoxybenzamine in the pre-operative preparation of patients with phaeochromocytoma.