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The relative virulence of 109 Ascochyta isolates collected from pea fields in Alberta from 1996 to 1998 were evaluated on 10-day-old seedlings by the excised leaf-assay technique. Twenty-eight isolates were avirulent, while the others produced lesions of various sizes on pea leaves. DNA samples from 86 isolates were amplified by the RAPD technique using PCR with single primers. One dominant genotype of Ascochyta pisi was identified throughout Alberta, but variations in virulence were not clearly differentiated by the RAPD technique. Five Ascochyta isolates, four virulent and one avirulent, were used to assess the susceptibility of 20 field pea cultivars available in Alberta, including 13 yellow types and seven green types. Based on symptom development, the yellow-type cultivars Swing, Eiffel and Delta, and the green-type cultivar Orb, were the most susceptible. Of yellow-type cultivars, Voyageur, Carneval and Montana were most resistant to Ascochyta infection.

Greenhouse studies showed that root inoculation had significant effects on sclerotinia blight (Sclerotinia sclerotiorum) of coneflower (Echinacea sp.). Seedling wilt and root rot symptoms caused by S. sclerotiorum were most severe when inoculum was placed in direct contact with seedling roots, and diminished as the distance of the inoculum from the roots increased. When colonized agar disks, colonized oat grains and sclerotia as inoculum sources were evaluated on E. angustifolia, grain inoculum was the most virulent and sclerotia the least. An in vitro bioassay was conducted, and a logistic dose-response model was developed for the fungicides benomyl, vinclozolin, iprodione and dicloran. The first three fungicides were further evaluated in greenhouse experiments. Benomyl was the most effective in controlling S. sclerotiorum in both bioassay and greenhouse evaluations. The same three fungicides were evaluated in two field experiments in Alberta, where all were effective in reducing disease incidence. Key words: Echinacea sp., Sclerotinia sclerotiorum, dose-response model

Aims/hypothesis. Diabetes-induced activation of protein kinase C has been associated with the development of vascular complications. Elevated de novo diacylglycerol synthesis has been postulated to underlie this protein kinase C activation. Diabetes also increases the circulating concentrations of non-esterified fatty acids, which are immediate precursors of diacylglycerol through the de novo pathway. We hypothesized that increased fatty acids contribute to de novo diacylglycerol synthesis and activation of protein kinase C in vascular cells. Methods. Primary cultures of porcine carotid smooth muscle cells were exposed to fatty acids, bound to albumin in physiologic ratios. Diacylglycerol and triacylglycerol were measured in extracts of these cells. Protein kinase C activation was measured as membrane translocation with isoform-specific antibodies. Results. Saturated fatty acids caused considerable accumulation of diacylglycerol through de novo synthesis. Unsaturated fatty acids increased triacylglycerol, but not diacylglycerol. Platelet-derived growth factor activated the α, ɛ and ζ protein kinase C isoforms. Activation of the α and ζ isoforms was amplified by oleate pretreatment but inhibited by palmitate. In the absence of growth factor stimulation, neither palmitate nor oleate had any effect on the membrane/cytosol distribution of any protein kinase C isoform. Conclusion/interpretation. Saturated fatty acids elicited de novo diacylglycerol synthesis in vascular smooth muscle cells without activating protein kinase C. Effects of fatty acids on protein kinase C activation by platelet-derived growth factor did not correlate with the effects on de novo diacylglycerol synthesis. These results indicate that de novo diacylglycerol synthesis is, by itself, insufficient to activate protein kinase C. [Diabetologia (2000) 43: 1136–1143]

The frequency range below a few tens of MHz is unexplored with high angular resolution due to the opacity of Earth's ionosphere. An interferometer array in space providing arcminute angular resolution images at frequencies of a few MHz would allow a wide range of problems in solar, planetary, galactic, and extragalactic astronomy to be attacked. These include the evolution of solar radio emissions associated with shocks driven by coronal mass ejections and searches for coherent radio emission from supernova remnants and relativistic jets. In addition, it is likely that unexpected objects or emission processes will be discovered by such an instrument, as has always happened when high resolution astronomical observations first become possible in a new region of the electromagnetic spectrum. The Astronomical Low Frequency Array (ALFA) mission will consist of 16 identical small satellites forming an aperture synthesis array. The satellites will cover the surface of a spherical region ≈ 100 km in diameter, thus providing good aperture plane coverage in all directions simultaneously. The array will operate in two medes: 1) “snapshot” imaging of strong, rapidly changing sources such as solar radio bursts and 2) long-term aperture synthesis observations for maximum sensitivity, high dynamic range imaging. In both cases a large number of array elements is needed.

The Oporto radiospectrograph and the Nancay radioheliograph recorded a radio event on November 6, 1997, closely related in time with a flare on National Oceanic and Atmospheric Administration (NOAA) active region 8100. At the beginning of the event the radio sources are located on a rather small volume in the vicinity of the flare site. In a timescale of only a few minutes the radio emission sites spread over a large volume in the corona, covering a range of 100° in heliolatitude. During the period of the radio event the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO) observed an extremely fast coronal mass ejection (CME), with a velocity around 2000 km s -1 . This CME presents the particularity of having a fast lateral expansion, giving it a shape reminiscent of a coat hanger. There is a very good association between the latitudinal extent and time development of the CME seen by LASCO and the radio sources recorded by the radio instruments.

The English language medical literature was reviewed to determine the strength of the published evidence for the assertion that dimercaptosuccinic acid scintigraphy (DMSA) is superior to ultrasound (US) in the detection of established renal scarring in children. The MEDLINE database was used to identify papers published between 1985 and 1997 that claimed to be concerned with the detection of scars, and contained sufficient information to permit calculation of the sensitivity of US relative to DMSA. Only 10 studies were identified. The sensitivity of US for scarring, using DMSA as a gold standard, ranged from 37% to 100%, and its specificity from 65% to 99%. These wide ranges mean that evaluation of the role of US in the detection of scarring remains controversial. All papers contained methodological flaws. Allowing for these, the sensitivity of US appears to be acceptable. Further research that avoids these methodological problems is required.

We present observations of two coronal mass ejections (CMEs) observed by the LASCO and EIT instruments on board the Solar and Heliospheric Observatory. One was observed on 1997 April 30 and the other on 1997 February 23. The latter CME is accompanied by a spectacular prominence eruption and reaches velocities of about 900 km s-1, while the former has no apparent accompanying prominence eruption and attains velocities of only about 300 km s-1. However, the two CMEs are similar in appearance, having bright circular rims that can be interpreted as marking the apexes of expanding magnetic flux ropes, and both can be tracked from their origins near the surface of the Sun out to great distances. We compare the kinematic and morphological properties of these CMEs with an MHD model of an erupting flux rope and find that the CMEs can be successfully modeled in this manner.

This study presents data on two events from the Extreme-UV Imaging Telescope (EIT) and the Large Angle and Spectroscopic Coronagraph instruments (C1, C2, and C3), Geostationary Operational Environmental Satellite (GOES) soft X-ray data, and 40-800 MHz radio spectra of the Astrophysical Institute Potsdam. At first glance, the two events appear similar. However, one event decays after a flare-related ejection of cold and hot matter into the lower corona causing only brightness changes in EIT and C1, while the other event marks the onset of a coronal mass ejection (CME) that propagates with a leading-edge speed of ≈530 km s-1 between 2 and 30 R☉. The radio data reveal two differences between the CME and non-CME events: (1) a characteristic faint type III burst group in the time interval with the first clearly CME-related structural change in the coronagraph images and (2) a continuum emission with a frequency drift during the passage of the CME matter through the C1 field of view. Furthermore, we show that the radio spectral data can provide essential information on the timing of the early stages of CME formation and the initial mass motions associated with the ejection.

The near-rigid rotation of the corona above the differential rotation of the photosphere has important implications for the form of the global coronal magnetic field. The magnetic reconfiguring associated with the shear region where the rigidly-rotating coronal field lines interface with the differentially-rotating photospheric field lines could provide an important energy source for coronal heating. We present data on coronal rotation as a function of altitude provided by the Large Angle Spectrometric Coronagraph (LASCO) instrument aboard the Solar and Heliospheric Observatory (SOHO) spacecraft. LASCO comprises of three coronagraphs (C1, C2, and C3) with nested fields-of-view spanning 1.1 R⊙ to 30 R⊙. An asymmetry in brightness, both of the Fe xiv emission line corona and of the broad-band electron scattered corona, has been observed to be stable over at least a one-year period spanning May 1996 to May 1997. This feature has presented a tracer for the coronal rotation and allowed period estimates to be made to beyond 15 R⊙, up to 5 times further than previously recorded for the white-light corona. The difficulty in determining the extent of differential motion in the outer corona is demonstrated and latitudinally averaged rates formed and determined as a function of distance from the Sun. The altitude extent of the low latitude closed coronal field region is inferred from the determined rotation periods which is important to the ability of the solar atmosphere to retain energetic particles. For the inner green line corona ( 2.5 R⊙) we determine a rotation period of (27.7±0.1) days.

Measurements of the mean magnetic field of the Sun (MMFS) seen as a star were regularly conducted at the Mount Wilson Observatory from 1970 October through 1982 December. A listing is presented of all these data (2457 daily values) suitable for comparison with similar data of other observatories and for studies of magnetic variability and rotation of the Sun. The scatter-plot diagrams and power spectra of the Mount Wilson data and also of the total data 1968-1991 (collected from three observatories: Crimean Astrophysical Observatory, Mount Wilson Observatory, and Wilcox Solar Observatory) are also presented. Time variations of the MMFS connected with solar rotation at periods ≈ 27-28 days and also an enigmatic 1 yr variation are briefly discussed. The power spectrum of the 24 yr data set shows that the most significant and phase-coherent synodic periods of the MMFS variations are 26.92 ± 0.02 and 27.13 ± 0.02 days (both are thought to be associated with rotation of the large-scale surface magnetic field near equator of the Sun) and 28.13 ± 0.02 days. It is suggested that the latter period reflects "rigid" rotation of the global magnetic field concentrated under the bottom of the solar convection zone. The arguments are given in favor of reality and high confidence level of major periodicities exhibited by MMFS variations.

The fungus Pestalotia malicola attacks fruits of Chinese quince ( Chaenomeles sinensis ) in Japan. Scanning electron microscopy (SEM) in combination with micromanipulation as well as cryo SEM demonstrated that the fungus was growing on, within, and beneath the fruit cuticle. The ability of the pathogen to grow in association with the cuticle suggested that the fungus produces cutinase(s) and/or non-specific esterase(s). Enzyme assays revealed that the fungus produced an enzyme, or enzymes, with activities characteristic of a cutinase and a non-specific esterase when cultured on cucumber cutin as the sole carbon source. The same enzyme activities were also demonstrated to be constitutively present in the extracellular matrix that surrounds conidia in conidiomata.

The development of a coronal mass ejection on 9 July 1996 has been analyzed by comparing the observations of the LASCO/SOHO coronagraphs with those of the Nancay radioheliograph. The spatial and temporal evolution of the associated radioburst is complex and involves a long-duration continuum. The analysis of the time sequence of the radio continuum reveals the existence of distinct phases associated with distinct reconnection processes and magnetic restructuring of the corona. Electrons are accelerated in association with these reconnection processes. An excellent spatial association is found between the position and extension of the radio source and the CME seen by LASCO. Furthermore, it is shown that the topology and evolution of the source of the radio continuum involve successive interactions between two systems of loops. These successive interactions lead to magnetic reconnection, then to a large scale coronal restructuring. Thus electrons of coronal origin may have access to the interplanetary medium in a large range of heliographic latitudes as revealed by the Ulysses observations.

Solar activity in the latter half of 1996 was dominated by the presence of an extended filament channel in the southern hemisphere, forming a switchback configuration where it merged with the polar crown. Several large coronal mass ejections (CMEs) were observed to originate on or near this magnetic neutral line by the LASCO and EIT instruments on SOHO. As this channel gradually disappeared, a new, extended channel formed to the west of the old one, and this new channel also produced a number of large CMEs. We report here on observations of two events (December 23, 1996 and February 7,1997), and discuss the global nature of these events.

We employ coronal extrapolations of solar magnetograph data to interpret observations of the white-light streamer structure made with the LASCO coronagraph in 1996. The topological appearance of the streamer belt during the present minimum activity phase is well described by a model in which the Thomson-scattering electrons are concentrated around a single, warped current sheet encircling the Sun. Projection effects give rise to bright, jet-like structures or spikes whenever the current sheet is viewed edge-on; multiple spikes are seen if the current sheet is sufficiently wavy. The extreme narrowness of these features in polarized images indicates that the scattering layer is at most a few degrees wide. We model the evolution of the streamer belt from 1996 April to 1996 September and show that the effect of photospheric activity on the streamer belt topology depends not just on the strength of the erupted magnetic flux, but also on its longitudinal phase relative to the background field. Using flux transport simulations, we also demonstrate how the streamer belt would evolve during a prolonged absence of activity.

SOHO EIT spectroheliograms showing the polar coronal holes during the present sunspot minimum are compared with National Solar Observatory (Kitt Peak) magnetograms taken in Fe I λ8688 and Ca II λ8542. The chromospheric λ8542 magnetograms, obtained on a routine, near-daily basis since 1996 June, reveal the Sun's strong polar fields with remarkable clarity. We find that the Fe IX λ171 polar plumes occur where minority-polarity flux is in contact with flux of the dominant polarity inside each polar hole. Moreover, the locations of "plume haze" coincide approximately with the patterns of brightened He II λ304 network within the coronal hole. The observations appear to be consistent with mechanisms of plume formation involving magnetic reconnection between unipolar flux concentrations and nearby bipoles. The fact that minority-polarity fields constitute only a small fraction of the total magnetic flux within the polar holes suggests that plumes are not the main source of the high-speed polar wind.

An assay was developed for the characterization of a tobacco rattle virus (TRV) isolate from potato tubers exhibiting disease symptoms resembling corky ringspot disease. Using reverse transcription and the polymerase chain reaction. cDNA of this TRV isolate was obtained for the 16 kDa open reading frame located on RNA-1. Amplified cDNA was cloned and sequenced to confirm the identity of the virus and to determine the relationship of this isolate to other sequenced TRV isolates. Disease symptoms and virus morphology were also examined and used to characterize this Canadian TRV isolate. Deduced amino acid sequence of the recovered TRV isolate had a high level of homology (97.9%) with the PLB isolate of TRV from The Netherlands.

Based on a Dissertation read before the Royal Medical Society on Friday, 23rd October, 1964 Not until the start of the 20th century did the organisation of rehabilitation services on a comprehensive scale develop. In this, Britain played a leading role largely due to the influence and leadership of one great man—Sir Robert Jones. Robert Jones was selected in the 1890’s to organise the first unified accident service in Great Britain, which was set up to deal with the injuries sustained by the large body of men employed in the construction of Manchester Ship Canal. The social conscience of the time did not include rehabilitation per se in the accident service, but the experience gained there by the young surgeon bore fruit in the First World War when as a famous orthopaedic surgeon, he was given the task of organising special military hospitals with full rehabilitation facilities.

TABLE OF CONTENTS THE HISTORY AND EVOLUTION OF PLASTIC SURGERY: A.B. Wallace, M.Sc, F.R.C.S.Ed. SYSTEMIC LUPUS ERYTHEMATOSUS: R. McD. Fox MUSCLE SPINDLES: A.J. Strong, B.A J. B. BAIKIE—DOCTOR AND EXPLORER: J.B. King, M.D., F.R.C.P.Ed. RES MEDICA LOOKING TOWARDS POST-GRADUATE EDUCATION FROM OUR LIBRARY REHABILITATION SERVICES FOR THE INJURED: R.R.S. Howard ASPECTS OF HOMEOPATHY: I.J. McKee

Several key performance parameters of shipboard power systems are affected by the grounding scheme applied. The grounding scheme impacts the nature of voltage transients during switching events and faults, identifiability and locatability of ground faults, fault current levels, and power quality. Power system simulations play an important role in choosing an appropriate grounding scheme and optimizing its components. The tools typically used for power system analysis need to be carefully tested to determine if they are appropriate for modeling effects of different grounding schemes and in particular the high frequency transients. This paper sheds light on modeling and validation techniques specific to grounding models. Furthermore, insight is provided to present research into new types of power system modeling techniques based on scattering parameters for improved accuracy at higher frequencies of interest. A testbed designed to study the impact of different types of grounding schemes is also introduced and first characterization measurements in the frequency domain provided. The paper concludes with an outlook to future work, which will focus on rigorous validation of the models developed.

Enterolert (IDEXX Laboratories Inc., Westbrook, Maine), a semiautomated, most probable number method for enumeration of enterococci, was compared with the standard membrane filter method by parallel testing of 138 marine and freshwater recreational bathing water samples. No statistically significant difference and a strong linear correlation were found between methods. Culturing of 501 Enterolert test wells resulted in false-positive and false-negative rates of 5.1 and 0.4%, respectively. Less time for setup, incubation (24 versus 48 h), and reading of Enterolert permits more efficient monitoring of recreational bathing areas.

Activated B cells express Fas (CD95) and are targets for apoptosis induced by CD4+ Th1 effector cells that kill in a Fas-dependent fashion. We report here that IL-4 reverses the susceptibility to Fas-mediated apoptosis that characterizes CD40-stimulated primary B cells. IL-4-induced Fas resistance is not associated with an alteration in the elevated level of Fas expression produced by CD40 ligand and does not depend on additional receptor-mediated signals. However, IL-4-induced resistance to Th1 cell-mediated cytotoxicity (Th1-CMC) develops more slowly than resistance mediated by surface Ig and is not affected by protein kinase C depletion, unlike anti-Ig-induced Fas resistance. By these two criteria, IL-4-and anti-Ig-induced resistance to Th1-CMC appear to be driven through distinct mechanisms; in keeping with this, suboptimal doses of IL-4 and anti-Ig act in synergy to induce marked protection against Th1-CMC. An important role for IL-4-induced Fas resistance is suggested by the observation that sera from IL-4-overexpressing transgenic mice contain autoreactive Abs.

(1996). Cultural control of plant diseases: a historical perspective. Canadian Journal of Plant Pathology: Vol. 18, No. 2, pp. 145-150.

Some preliminary results of time-resolved waveforms of Langmuir waves in the foreshock region are presented. There is evidence for both three-wave parametric decay and modulational instability. Also strong incoherent waves in the bow shock are shown.

Summary Respiratory and sleep disturbances may be important causes of morbidity in Steele-Richardson-Olszewski syndrome but the frequency and character of nocturnal abnormalities remains uncertain. A prospective study of 11 patients with Steele-Richardson-Olszewski syndrome and age-matched control subjects was undertaken using clinical assessments, a structured sleep questionnaire, spirometry, static maximum inspiratory and expiratory pressures and nocturnal oximetry. The mean age of the Steele-Richardson-Olszewski syndrome patients was 63.2 (52-70) years and mean disease duration was 4.0 (2-6) years. There was moderate to severe motor disability in nine and mild to moderate dementia in eight. In the patients with Steele-Richardson-Olszewski syndrome the following abnormalities contributed to sleep disturbances significantly more frequently than in normal controls: depression, dysphagia, frequent nocturnal awakenings (usually associated with urinary frequency), immobility in bed, difficulty with transfers, impaired dressing and feeding. There was profound impairment of voluntary respiratory control whilst automatic and limbic control were well maintained. Nocturnal respiratory abnormalities were not present even in the most severely disabled. In Steele-Richardson-Olszewski syndrome sleep abnormalities are common; they relate to the cognitive, pseudobulbar and extrapyramidal disturbances and may therefore be amenable to symptomatic control.

Some theories of the generation of 2ωpe radiation, in the upstream solar wind, invoke the notion of nonlinear wave-wave interactions. We present observations, from the WIND spacecraft, of an event in the upstream solar wind with first and second harmonic emissions. The bicoherence spectrum of this event shows coherence amongst components that suggest three-wave interactions of the type described in (Cairns and Melrose, 1985). We discuss this result and its theoretical context.

The Large Angle Spectroscopic Coronagraph (LASCO) is a triple coronagraph being jointly developed for the Solar and Heliospheric Observatory (SOHO) mission. LASCO comprises three nested coronagraphs (C1, C2, and C3) that image the solar corona for 1.1 to 30 solar radii (C1: 1.1 to 3 solar radii, C2: 1.5 to 6 solar radii, and C3: 3 to 30.0 solar radii). The inner coronagraph (C1) is a newly developed mirror version of the classic Lyot coronagraph without an external occultor, while the middle coronagraph (C2) and the outer coronagraph (C3) are externally occulted instruments. High resolution coronal spectroscopy from 1.1 to 3 R solar radii can be performed by using a Fabry-Perot interferometer, which is part of C1. High volume memories and a high speed microprocessor enable extensive onboard image processing. Image compression by factors of 10 to 20 will result in the transmission of 10 to 20 full images per hour.

A method for calculating the first static hyperpolarisability (β0) values of donor-acceptor molecules using a desktop molecular modelling package is presented. The β0 values are deduced from a two-state model using geometries from AM1 and dipole moments from ZINDO/s calculations. The estimated β0 values are in reasonable agreement with reported EFISH values. This method involves the use of a conventional PC and a molecular modelling package and does not require powerful workstations or long computational times.

CD40L, a membrane protein of activated T cells, interacts with the B cell receptor CD40. This interaction has been implicated in the rescue of germinal center B cells from apoptosis and in the rescue of WEHI-231 B lymphoma cells from sIg-induced apoptosis. In this report, we have demonstrated that the signal mediated by CD40L acts upon bcl-x, a bcl-2 homologue. bcl-x expression is strongly enhanced by CD40 receptor engagement, while there is little or no induction by sIg cross-linking. The expression of bax and bcl-2 is not significantly affected by either CD40L or sIg cross-linking. Antisense but not sense phosphorothioate oligonucleotide for bcl-x can partially block this CD40-mediated apoptotic rescue. This result suggests that the up-regulation of bcl-x by CD40L plays an important role in CD40-mediated apoptotic rescue in murine B cells.

A prospective electrophysiological study of phrenic nerve was performed in 59 subjects undergoing open-heart surgery. The nerve was stimulated percutaneously at the neck and the diaphragmatic response was recorded with surface electrodes placed over the 8th intercostal space. The latency, amplitude, duration and area of the evoked response were measured before and after the operation. Post-operatively no response was elicited in 2 patients bilaterally, in 5 from the left and in 2 from the right. Comparison of the post-operative with the pre-operative group values in the remaining subjects showed that the amplitude and area of the left phrenic were lower in the post-operative study, indicating that some of the nerve fibres were not conducting. There were no statistically significant differences between pre and post-operative values of latency or duration on the left or any of the parameters on the right. Our findings suggest that the amplitude and area of the diaphragmatic response are more sensitive than latency in detecting phrenic nerve paresis associated with open-heart surgery.

Organ procurement organizations (OPOs) report a nearly fourfold difference in donor availability as measured by eligible deaths per million population (PMP) based on hospital referrals. We analyzed whether mortality data help explain geographic variation in organ supply as measured by the number of eligible deaths for organ donation. Using the 2007 National Center for Health Statistics' mortality data, we analyzed deaths occurring in acute care hospitals, aged ≤ 70 years from cerebrovascular accidents and trauma. These deaths were mapped at the county level and compared to eligible deaths reported by OPOs. In 2007, there were 2 428 343 deaths reported in the United States with 42 339 in-hospital deaths ≤ 70 years from cerebrovascular accidents (CVA) or trauma that were correlated with eligible deaths PMP (r(2) = 0.79.) Analysis revealed a broad range in the death rate across OPOs: trauma deaths: 44-118 PMP; deaths from CVA: 34-118 PMP; and combined CVA and trauma: 91-229 PMP. Mortality data demonstrate that deaths by neurologic criteria of people who are likely to be suitable deceased donors are not evenly distributed across the nation. These deaths are correlated with eligible deaths for organ donation. Regional availability of organs is affected by deaths which should be accounted for in the organ allocation system.

This study examined the effect of transfer of a 2.4 Mbp region of Brown Norway (BN) rat Chr 1 into the Fawn Hooded Hypertensive (FHH) genetic background on autoregulation (AR) of cerebral blood flow (CBF) and the myogenic response of isolated middle cerebral arteries (MCA). Autoregulation of CBF measured by laser Doppler flowmetry was poor in FHH rats (AR index (AI), 0.8±0.1) and in FHH.1BN congenic strains which excluded the critical region (AR-: AI, 0.9± 0.1). In contrast, autoregulation of CBF was completely restored by transfer of the region of BN Chr 1 between 258.8 to 261.2 Mbp in AR+ FHH.1BN congenic strains (AI, 0.3 ± 0.1). The diameter of MCA of FHH rats and AR- congenic strains increased by ∼10% (140 ± 1 to 157± 2 μm), when transmural pressure was increased from 40 to 140 mmHg. In contrast, the diameter of the MCA in AR+ congenic strain fell from 127 ± 2 to 65 ± 1 μm. Whole-cell patch-clamp of cerebral VSM cells revealed a 4.3- fold increase in BK channel current densities at depolarized potentials in FHH versus AR+ rats (105 ± 2 versus 24 ± 4 pA/pF at +80mV). Using single channel analysis we found that the increase in BK channel current was largely due to a marked increase in the NPo of BK channel in FHH as compared to AR+ rats (0.9 ± 0.1 and 0.2 ± 0.1 at +80mV). To explore the significance of the impaired myogenic response, we compared changes in CBF and infarct size following transient occlusion and reperfusion of the MCA in FHH rats and the AR- and AR+ congenic strains. Occlusion of MCA reduced CBF similarly in all the strains. However, the hyperemic response following reperfusion in FHH and AR- strains was significantly greater and more prolonged than that seen in AR+ rats (AR-: 173 ± 1%, 45 min versus AR+: 124 ± 5%, 15 min). Moreover, infarct size and edema formation was significantly greater in the AR- congenic strain (39 ± 3 % and 12 ± 2 %) in comparison to that seen in the AR+ strain (28 ± 2 % ; 7 ± 1%). These results indicate that there is a gene that plays a critical role in the regulation of the myogenic response of the cerebral vasculature by altering BK channel activity in the critical 2.4 Mb region of Chr 1 containing just 15 genes and that transfer of this region from BN to FHH rats restores autoregulation of CBF, vascular reactivity and reduces infarct size following ischemia/reperfusion injury.

The pace of research and development in the neurosciences remains breathtaking. This brief review attempts to highlight some of the areas in which very recent scientific and clinical advances have led to a greater understanding of the pathophysiology and management of neurological disease. The constraints of this paper prevent coverage of many important fields of neurological research, including infectious diseases, headache, muscle disease, interventional radiology, neuroepidemiology, and neuropsychiatry. Evidence for a strong genetic influence in multiple sclerosis continues to accumulate from twin studies, which show consistently high monozygotic concordance and also increased dizygotic concordance in twins compared with non-twin siblings.1 Susceptibility to multiple sclerosis seems unlikely to be determined by a single dominant or even recessive gene but is more likely to be polygenic. A study of pregnancy and multiple sclerosis showed a threefold increase in the relapse rate during the first three postpartum months, and these relapses were more severe than those during pregnancy. There was no changes in the relapse rate during pregnancy.2 The diagnostic role of magnetic resonance imaging is well established and the technique is increasingly used to monitor disease activity and treatments. The use of gadolinium enhancement has been shown greatly to increase the sensitivity of successive monthly brain scans in monitoring the treatment of relapsing and remitting or secondary progressive multiple sclerosis. Powerful prognostic information is provided by brain scans in patients who present with an acute clinically isolated syndrome suggestive of multiple sclerosis.3 After five years 65% of patients who had asymptomatic white matter lesions at presentation had developed clinically definite multiple sclerosis, compared with 3% of patients with normal scan results at presentation. The disease progressed rapidly if the scan showed four or more lesions at presentation, and a greater number of lesions also correlated with development of moderate …

We have previously shown an increased percentage of gamma delta T cells expressing the TCR V delta 1 gene segment in the peripheral blood and bronchoalveolar lavage fluid of patients with systemic sclerosis (SSC). To estimate clonality of these V delta 1+ T cells, the diversity of V delta 1 junctional regions (V-D-J) was examined using a reverse transcriptase-PCR to amplify TCR delta-chain transcripts isolated from PBMC, lung, esophagus, stomach, or skin of patients and controls. Limited diversity of V delta 1-J delta junctional regions in SSC patients was demonstrated by comparing the size distribution of PCR-amplified junctional region cDNA from patients with that of controls. Sequence analyses confirmed that V delta 1-J delta junctional regions from the blood of SSc patients had less diversity than those from controls, in that a significantly higher proportion of sequences were repeated in patients (54.4 vs 19.4% in controls). Evidence for selection of the V delta 1+ T cells in the tissues of SSC patients came from the findings that the same V delta 1-J delta junctional sequences persisted in an individual patient over time and that identical junctional sequences were isolated from multiple sites. Analysis of deduced amino acid sequences revealed two clusters of similarities among the junctional regions from patients. These data suggest that expansion of V delta 1+ gamma delta T cells may be Ag driven in SSC patients.

“Smart” structures with integrated sensors, actuators, and control electronics are of importance to the next-generation high-performance structural systems. Piezoelectric materials possess unique electromechanical properties, the direct and converse effects, which, respectively, can be used in sensor and actuator applications. In this study, piezothermoelastic characteristics of piezoelectric shell continua are studied and applications of the theory to active structures in sensing and control are discussed. A generic piezothermoelastic shell theory for thin piezoelectric shells is derived, using the linear piezoelectric theory and Kirchhoff-Love assumptions. It shows that the piezothermoelastic equations, in three principal directions, include thermal induced loads, as well as conventional electric and mechanical loads. The electric membrane forces and moments induced by the converse effect can be used to control the thermal and mechanical loads. A simplification procedure, based on the Lame´ parameters and radii of curvatures, is proposed and applications of the theory to (1) a piezoelectric cylindrical shell, (2) a piezoelectric ring, and (3) a piezoelectric beam are demonstrated.

Increased Na+/H+ antiport activity has been implicated in the pathogenesis of hypertension and vascular disease in diabetes mellitus. The independent effect of elevated extracellular glucose concentrations on Na+/H+ antiport activity in cultured rat vascular smooth muscle cells (VSMC) was thus examined. Amiloride-sensitive 22Na+ uptake by VSMC significantly increased twofold after 3 and 24 h of exposure to high glucose medium (20 mM) vs. control medium (5 mM). Direct glucose-induced Na+/H+ antiport activation was confirmed by measuring Na(+)-dependent intracellular pH recovery from intracellular acidosis. High glucose significantly increased protein kinase C (PKC) activity in VSMC and inhibition of PKC activation with H-7, staurosporine, or prior PKC downregulation prevented glucose-induced increases in Na+/H+ antiport activity in VSMC. Northern analysis of VSMC poly A+ RNA revealed that high glucose induced a threefold increase in Na+/H+ antiport (NHE-1) mRNA at 24 h. Inhibiting this increase in NHE-1 mRNA with actinomycin D prevented the sustained glucose-induced increase in Na+/H+ antiport activity. In conclusion, elevated glucose concentrations significantly influence vascular Na+/H+ antiport activity via glucose-induced PKC dependent mechanisms, thereby providing a biochemical basis for increased Na+/H+ antiport activity in the vascular tissues of patients with hypertension and diabetes mellitus.

Processing of vanadiferous slags through the pyrometallurgical process route appears to offer advantages both in terms of ferroalloy production and in the potential for efficient vanadium recovery from hot metal. In order to investigate the effect of slag composition on the phase distribution of vanadium, a series of laboratory smelting experiments was carried out. The effect of basicity adjustments on the slag/metal distribution of iron, vanadium, and manganese was investigated using carbon and FeSi as a reductant. A simulation of the final stage of slag reduction was also carried out to determine the efficiency of vanadium recovery during metallothermic smelting using aluminum and FeSi.

We obtained Carrington-rotation-averaged daily rates of coronal mass ejections (CMEs), corrected for duty cycle, for the period 1979-1989. The 27-day averages of CME rate and sunspot number are correlated over this 11-yr period, although significant discrepancies can occur for any given rotation. The baseline CME rate exhibited quasi-discontinuities in 1982 (decrease) and 1988 (increase) when the “tilt angle” of the heliospheric current sheet passed through values of ∼ 50°. We suggest that these quasi-discontinuities are related to the dynamics of the belts of polar crown filaments that reside at ∼ 50° north and south of the equator during solar minimum and move poleward during the rise phase of the solar cycle.

Language impairment in Alzheimer's disease occurs early, and language function deteriorates with progression of the illness to cause significant disability. This review focuses on language dysfunction in Alzheimer's disease and the contribution of semantic memory impairment.Electronic publication databases were searched for literature relevant to the review. Additionally, individual references were examined to elicit further studies not found by online search.Language impairment in Alzheimer's disease initially affects verbal fluency and naming before breakdown in other facets. Naming and fluency require integrity of semantic concepts, and dysfunction may be a marker of primary semantic memory impairment rather than overall cognitive decline. Research suggests the presence of semantic loss several years prior to diagnosis. Imaging studies indicate an altered connectivity state with respect to language networks, and this is associated with potential semantic failure. This state may also be present in individuals with established risk factors for Alzheimer's disease. Compensatory recruitment of alternative cortical areas to supplement language function appears to occur and may be a target for future intervention.Identifying and classifying the nature and degree of language impairment more closely could aid in developing targeted therapies. Treatments already established in other aphasic states, such as post-stroke, may be especially relevant. The nature of these and the protective nature of cognitive reserve are potential therapeutic avenues.

Internal fruit rot, caused by Fusarium lactis, is an important disease of sweet pepper (Capsicum annuum) in Canadian greenhouses. Production of the mycotoxins fumonisin B₁ (FB₁), moniliformin (MON) and beauvericin (BEA) by F. lactis (17 isolates) and the related species F. proliferatum (three isolates) and F. verticillioides (one isolate), which are also associated with internal fruit rot, was evaluated on rice medium. All 21 isolates examined were found to produce BEA, at concentrations ranging from 13.28 to 1674.60 ppm, while 13 of 17 F. lactis isolates and two of three F. proliferatum isolates produced MON (0.23 to 181.85 ppm). Only one isolate of F. lactis produced detectable levels of FB₁ in culture, whereas all three F. proliferatum isolates and the F. verticilloides isolate produced this mycotoxin (0.28 to 314 ppm). Production of FB₁, MON and BEA was also evaluated in inoculated pepper fruits showing mild or severe symptoms of infection. FB₁ could be detected in both lightly and heavily diseased fruit tissue after inoculation with F. lactis, F. proliferatum or F. verticilloides, at concentrations ranging from 0.61 to 8.04 ppm. BEA was also detected in lightly and heavily diseased fruit tissue inoculated with F. lactis, as well as in heavily diseased tissue inoculated with F. proliferatum (3.00 to 19.43 ppm), but not in tissue inoculated with F. verticilloides. MON was detected in all tissues inoculated with F. proliferatum or F. verticilloides, and in heavily diseased tissue inoculated with F. lactis (0.03 to 0.27 ppm). The three mycotoxins were also found in naturally infected sweet pepper fruits exhibiting symptoms of internal fruit rot and collected from a commercial greenhouse. The production of MON, BEA and FB₁ alone or in combination by isolates of F. lactis suggests that development of internal fruit rot of sweet pepper is an important food safety concern, and that every effort should be made to cull infected fruit before it makes it to market.

Three siblings presented with a progressive neurological disorder beginning in the third decade of life and characterised by palatal myoclonus, nystagmus, bulbar weakness and spastic tetraparesis. There was no evidence of intellectual deterioration or seizures. CT scan showed marked brainstem atrophy in two patients and basal ganglia calcification in one. MRI scan in one showed high signal in the brainstem and periventricular region and cerebral biopsy in this patient showed myelin loss and the presence of Rosenthal fibres. A similar disease affected the siblings' mother, maternal aunt and two of the aunt's daughters, suggesting an autosomal dominant mode of transmission of what appears to be a unique genetic disorder.

During the encounter of Ulysses with Jupiter, we have measured two components of the dc electric field and deduced from them the flow speed in the Io toms, as well as the presence of a polar cap region end what we interpret as a cleft region. Within the toms the flow speed is approximately equal to the speed of a plasma corotating with Jupiter but has significant deviations. The dominant deviations have an apparent period of the order of Jupiter's rotation period, but this might be a latitudinal effect. Other important periods are about 40 min and less than 25 min.

Lipids from the paracloacal glands of adult Chinese alligators (Alligator sinensis) were analyzed by gas chromatography/mass spectrometry. Acetates, aliphatic alcohols, free fatty acids and waxes consisting primarily of hexadecanoates were indicated in the secretions of males and females. Cholesterol, a diterpene hydrocarbon, and a diterpene ketone were detected in secretions of males but not in those of females. Lipids identified in the paracloacal secretions ofA. sinensis are compared with those reported from the American alligator and other crocodilians.

To examine the anatomic spread of caudal local anesthetic solution in children aged 1-7 years.To determine whether incremental increases in the volume of caudal injections of 0.5, 0.75, and 1.0 ml·kg(-1) result in reliable (90%) and potentially clinically significant increases in the number of vertebral segments reached.Caudal block is one of the most frequently performed pediatric regional analgesic techniques. Traditional formulae suggest that changes in the volume of caudal injectate in the range 0.5-1.0 ml·kg(-1) would have clinically useful effects.In a single blind design, 45 children aged 1-7 years undergoing caudal block received one of the three predetermined volumes (0.5, 0.75, and 1 ml·kg(-1) ) of local anesthetic solution containing radio-opaque contrast under controlled conditions. Following X-ray examination, the anatomic spread of the block was reported by a radiologist blinded to the volume of solution received.There were 15 children in each group, and they were similar in terms of age, height, and weight. Spread was observed between the 5th lumbar (L5) and 12th thoracic (T12) vertebral levels. A volume of 1 ml·kg(-1) results in a small but significantly greater spread of solution than 0.5 ml·kg(-1) (P0.05), but there was no difference between 0.5 and 0.75 ml or between 0.75 and 1.0 ml. No volume reliably reached a level higher than the second lumbar vertebra (L2).Incrementally increasing the volume of injectate between 0.5 and 1.0 results in a modest increase in the spread of the caudal solution. It is unlikely that volumes of1 ml will reliably reach a vertebral level that is higher than L2.

Fifteen plant species were collected from the Nelspruit Botanical Garden based on a list of plants provided by Phytomedicine Programme at the University of Pretoria and their ethnopharmacological information. Hexane, dichloromethane (DCM), acetone and methanolic extracts were screened forantimycobacterial activity against Mycobacterium smegmatis. The acetone extract of Milletia stulhimannii was the most active, showing activity against Mycobacterium smegmatis with minimum inhibitory concentration (MIC) value of 0.13 mg/ml. Acetone extracts for all plants had lower MIC values ranging between 0.11-1.25 mg/ml against M. smegmatis. Milletia stulhimannii, Albizia gummifera, Xanthocercis zambesiaca and Barringtonia racemosa have shown great potential as anti-tuberculosis agents. They were active against M. smegmatis with average MIC values of acetone extracts of 0.13 mg/ml.Keywords: Tuberculosis, Antimycobacterial activity, Milletia stulhimannii, Minimum inhibitory concentration

Acetone leaf extracts of Combretaceae species Combretum imberbe Wawra, Combretum nelsonii Duemmer, Combretum albopunctatum Suesseng, and Terminalia sericea Burch ex DC and a mixture of asiatic acid and arjunolic acid isolated from C. nelsonii were tested for antifungal activity against Candida albicans, Cryptococcus neoformans, Microsporum canis, and Sporothrix schenckii on wounds of immunocompromised Wistar rats. The therapeutic agents were selected based on low MIC values ranging 0.02-2.5 mg/mL and low toxicity (LC50) ranging 75.7-168.6 microg/mL. Seven circular, full-thickness wounds were made on the back skin of 24 Wistar rats, under general anesthetic and using an aseptic technique. Rats were infected with different fungal pathogens in groups of six. The treatments were administered topically using 20% concentrations of each extract in aqueous cream. Amphotericin B was used as positive control. Erythema, exudate, crust formation, swelling, and ulceration were used to determine the wound healing process. Throughout the experiment, body temperature, measured using a subcutaneous probe, and weight of the rats were found to be within normal ranges. Epithelial closure in all rats occurred by 17 days. There was no significant difference in contraction of the lesion areas treated with different extracts. The variability in erythema at each lesion in rats infected with different fungal pathogens differed with treatments; the lesion without treatment took a longer time to heal in all cases. Exudate formation was observed until day 12 in rats infected with C. albicans and day 8 in rats infected with C. neoformans. In lesions infected with M. canis and S. schenckii, exudate formation was observed until day 10. The treated group presented a rigid, dark, and thick crust formation after day 3 until day 15. During histopathological evaluations, scant fungi were noted in all the wounds, indicating that infection had occurred but had generally cleared. The antifungal potential of crude extracts of selected plants and a mixture of asiatic acid and arjunolic acid on the wounds of immunocompromised rats was confirmed. The extracts of these plants may possibly be further developed into drugs for topical treatment of fungally infected wounds.