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The chemical modification of ribosomal RNA and proteins is critical for ribosome assembly, for protein synthesis and may drive ribosome specialisation in development and disease. However, the inability to accurately visualise these modifications has limited mechanistic understanding of the role of these modifications in ribosome function. Here we report the 2.15 Å resolution cryo-EM reconstruction of the human 40S ribosomal subunit. We directly visualise post-transcriptional modifications within the 18S rRNA and four post-translational modifications of ribosomal proteins. Additionally, we interpret the solvation shells in the core regions of the 40S ribosomal subunit and reveal how potassium and magnesium ions establish both universally conserved and eukaryote-specific coordination to promote the stabilisation and folding of key ribosomal elements. This work provides unprecedented structural details for the human 40S ribosomal subunit that will serve as an important reference for unravelling the functional role of ribosomal RNA modifications.

The ability of ribosomes to translate the genetic code into protein requires a finely tuned ion and solvent ecosystem. However, the lack of high-resolution structures has precluded accurate positioning of all the functional elements of the ribosome and limited our understanding of the specific role of ribosomal RNA chemical modifications in modulating ribosome function in health and disease. Here, using a new sample preparation methodology based on functionalised pristine graphene-coated grids, we solve the cryo-EM structure of the human large ribosomal subunit to a resolution of 1.67 Å. The accurate assignment of water molecules, magnesium and potassium ions in our model highlights the fundamental biological role of ribosomal RNA methylation in harnessing unconventional carbon-oxygen hydrogen bonds to establish chemical interactions with the environment and fine-tune the functional interplay with tRNA. In addition, the structures of three translational inhibitors bound to the human large ribosomal subunit at better than 2 Å resolution provide mechanistic insights into how three key druggable pockets of the ribosome are targeted and illustrate the potential of this methodology to accelerate high-throughput structure-based design of anti-cancer therapeutics.

Summary • Seed dormancy and dormancy cycling are poorly understood at the molecular level, but are central to plant community development. This study focuses on the embryonic axes of deeply dormant seeds of Prunus avium (wild cherry). • Rapid amplification of cDNA ends (RACE), differential display and quantitative PCR were used to recover and monitor expression of cDNAs. • cDNAs similar to two dormancy-imposing genes were isolated; a serine/threonine protein-phosphatase 2C homologous to ABSCISIC ACID INSENSITIVE 1 and 2 (Pa-PP2C1), and the transcription factor ABSCISIC ACID INSENSITIVE 3 (Pa-ABI3). Two germination-associated cDNAs were recovered; aconitase (Pa-ACO1) and eukaryotic translation initiation factor 3 subunit 8 (Pa-eIF3 SUBUNIT 8). Cold-treatment reduced expression of Pa-PP2C1 and Pa-ABI3, consistent with roles in establishing primary dormancy; neither was induced by imposition of secondary dormancy. Expression of these genes was distinct from expression of Pa-ACO1 and Pa-eIF3-SUBUNIT 8. • Results were consistent with a role for ABI1/ABI2 and ABI3 homologues in primary dormancy of P. avium embryonic axes, but not secondary dormancy as control of germination appeared overridden by the tissues surrounding the embryo.

Declining firm entry and the aging incumbent firms have meaningful implications for sluggish U.S. aggregate productivity growth. We provide a framework to characterize the contributions to industry productivity growth across the firm age distribution then apply it to firm-level Census data. Several findings emerge: the relationship between firm age and productivity growth is downward sloping and convex; the magnitudes are substantial but fade quickly; selection and reallocation predominantly drive higher productivity growth of young firms. Our results suggest a cumulative drag on aggregate productivity of 3.1% since 1980 and are expanded upon with an IV strategy and standard model of firm dynamics.

The U.S. economy has been going through a striking structural transformation--the secular reallocation of employment across sectors--over the past several decades. We propose a decomposition framework to assess the contributions of various margins of firm dynamics to this shift. Using firm-level data, we find that at least 50 percent of the adjustment has been taking place along the entry margin, due to sectors receiving different shares of startup employment than their employment shares. The rest is mostly due to life cycle differences across sectors. Declining overall entry has a small but growing effect of dampening structural transformation.

Soft X-ray cryo-microscopy/tomography with its extraordinary capability to map vitreous cells with high absorption contrast in their full three-dimensional extent, and at a resolution exceeding super-resolution fluorescence microscopy, is a valuable tool for integrative structural cell biology. Focusing on cell biological applications, its ongoing methodological development gained momentum by combining it with fluorescence cryo-microscopy, thus correlating highly resolved structural and specific information in situ. In this chapter, we provide a basic description of the techniques, as well as an overview of equipment and methods available to carry out correlative soft X-ray cryo-tomography experiments on frozen-hydrated cells grown on a planar support. Our aim here is to suggest ways that biologically representative data can be recorded to the highest possible resolution, while also keeping in mind the limitations of the technique during data acquisition and analysis. We have written from our perspective as electron cryo-microscopists/structural cell biologists who have experience using correlative fluorescence/cryoXM/T at synchrotron beamlines presently available for external users in Europe (HZB TXM at U41-FSGM, BESSY II, Berlin/Germany; Carl Zeiss TXMs at MISTRAL, ALBA, Barcelona/Spain, and B24, DLS, Oxfordshire, UK).

Geobacillus pallidus RAPc8 (NRRL: B-59396) is a moderately thermophilic gram-positive bacterium, originally isolated from Australian lake sediment. The G. pallidus RAPc8 gene encoding an inducible nitrilase was located and cloned using degenerate primers coding for well-conserved nitrilase sequences, coupled with inverse PCR. The nitrilase open reading frame was cloned into an expression plasmid and the expressed recombinant enzyme purified and characterized. The protein had a monomer molecular weight of 35,790 Da, and the purified functional enzyme had an apparent molecular weight of approximately 600 kDa by size exclusion chromatography. Similar to several plant nitrilases and some bacterial nitrilases, the recombinant G. pallidus RAPc8 enzyme produced both acid and amide products from nitrile substrates. The ratios of acid to amide produced from the substrates we tested are significantly different to those reported for other enzymes, and this has implications for our understanding of the mechanism of the nitrilases which may assist with rational design of these enzymes. Electron microscopy and image classification showed complexes having crescent-like, "c-shaped", circular and "figure-8" shapes. Protein models suggested that the various complexes were composed of 6, 8, 10 and 20 subunits, respectively.

The U.S. economy has been going through a striking structural transformation — the secular reallocation of employment across sectors — over the past several decades. We propose a decomposition framework to assess the contributions of various margins of firm dynamics to this shift. Using firm-level data, we find that at least 50 percent of the adjustment has been taking place along the entry margin, owing to sectors receiving shares of start-up employment that differ from their overall employment shares. The rest is mostly the result of life cycle differences across sectors. Declining overall entry has a small but growing effect of dampening structural transformation.

In September 2004, the Loxahatchee River Estuary was affected by Hurricanes Frances and Jeanne, which resulted in a monthly rainfall record of 610 mm and abnormally high freshwater discharges to the system. The occurrence, density, and biomass ofSyringodium filiforme in the Loxahatchee River Estuary declined significantly following the September 2004 storms based on 15 mo of pre-hurricane monitoring and 12 mo of post-hurricane monitoring. Throughout posthurricane monitoring,S. filiforme showed no sign of recovery, thoughHalophila johnsonii increased considerably during the post-hurricane period. Freshwater discharges resulting from the September 2004 hurricanes lowered minimum daily salinity values to near zero and increased standard deviation of daily salinity values to 11‰. Extremely low minimum daily salinity values and high daily salinity fluctuations likely resulted in the observed decline ofS. filiforme. We advise the use of minimum daily salinity values when assessing seagrass habitat suitability or when modeling the effects of alternative water management scenarios.

The outer radiation belt injection, transport, acceleration and loss satellite (ORBITALS) is a small satellite mission proposed as a Canadian contribution to the satellite infrastructure for the International Living With a Star (ILWS) program. The ORBITALS will monitor the energetic electron and ion populations in the inner magnetosphere across a wide range of energies (keV to tens of MeV) as well as the dynamic electric and magnetic fields, waves and cold plasma environment which govern the injection, transport, acceleration and loss of these energetic and space weather critical particle populations. ORBITALS will be launched around 2010–2012 into a low-inclination GTO-like orbit which maximizes the long-lasting apogee-pass conjunctions with both the ground-based instruments of the Canadian Geospace Monitoring (CGSM) array as well as with the GOES East and West and geosynchronous communications satellites in the North American sector. Specifically, the ORBITALS will make the measurements necessary to gain fundamental new understanding of the relative importance of different physical acceleration and loss processes which are hypothesised to shape the energetic particle populations in the inner magnetosphere. The ORBITALS will also provide the raw radiation measurements at MEO altitudes necessary for the development of the next-generation of radiation belt specification models, and on-board experiments will also monitor the dose, single-event upset, and deep-dielectric charging responses of electronic components on-orbit. In this paper we outline the scientific objectives of the ORBITALS mission, discuss how the ORBITALS will lead to solutions to outstanding questions in inner magnetospheric science, and examine how the ORBITALS will complement other proposed inner magnetosphere missions in the ILWS era.

The contribution of nitric oxide (NO) to the antinatriuresis and antidiuresis caused by low-level electrical stimulation of the renal sympathetic nerves (RNS) was investigated in rats anaesthetized with chloralose-urethane. Groups of rats, n= 6, were given i.v. infusions of vehicle, l-NAME (10 microg kg(-1) min(-1)), 1400W (20 microg kg(-1) min(-1)), or S-methyl-thiocitrulline (SMTC) (20 microg kg(-1) min(-1)) to inhibit NO synthesis non-selectively or selectively to block the inducible or neuronal NOS isoforms (iNOS and nNOS, respectively). Following baseline measurements of blood pressure (BP), renal blood flow (RBF), glomerular filtration rate (GFR), urine flow (UV) and sodium excretion (U(Na)V), RNS was performed at 15 V, 2 ms duration with a frequency between 0.5 and 1.0 Hz. RNS did not cause measurable changes in BP, RBF or GFR in any of the groups. In untreated rats, RNS decreased UV and U(Na)V by 40-50% (both P < 0.01), but these excretory responses were prevented in l-NAME-treated rats. In the presence of 1400W i.v., RNS caused reversible reductions in both UV and U(Na)V of 40-50% (both P < 0.01), while in SMTC-treated rats, RNS caused an inconsistent fall in UV, but a significant reduction (P < 0.05) in U(Na)V of 21%. These data demonstrated that the renal nerve-mediated antinatriuresis and antidiuresis was dependent on the presence of NO, generated in part by nNOS. The findings suggest that NO importantly modulates the neural control of fluid reabsorption; the control may be facilitatory at a presynaptic level but inhibitory on tubular reabsorptive processes.

A cDNA clone encoding a presumed full-length glycine-rich ribonucleic acid (RNA) binding protein was isolated from a lambda-ZAP Express cDNA library generated from primarily nondormant Prunus avium (wild cherry) embryonic axes. The cDNA, designated Pa-RRM-GRP1 (Prunus avium RNA recognition motif glycine-rich protein 1), contains a single N-terminal RNA recognition motif (RRM) and single C-terminal glycine-rich domain. The glycine-rich domain is unusually long at 91 amino acids, 58 of which are glycines. The 534-base pair (bp) open reading frame (ORF) of this clone encodes a 178-amino-acid polypeptide with a predicted molecular weight of 17.33 kDa and pI of 7.84. Comparative sequence alignment of Pa-RRM-GRP1 reveals extensive homology to known and presumed glycine-rich RNA binding proteins from angiosperms and gymnosperms. Genomic Southern blot analysis suggests that this gene exists as a single copy in P. avium. Expression of this gene in P. avium embryonic axes during low-temperature dormancy-breaking treatments was studied and found to be induced by cold (3 degrees C) using real-time PCR of total cDNA supported by Northern blot analysis of total RNA. Expression dropped during prolonged storage at 3 degrees C and was reduced to control levels by interruption of cold treatment by warming to 20 degrees C.

Geomagnetic field–line resonances may be identified via the use of cross–phase analysis of data from two closely spaced meridional ground–based magnetometer stations. It has been demonstrated that preprocessing of the data using a wavelet–based filter, chosen with regard to the variance of coefficients of the wavelet components, can be used to remove both low–frequency trend and large amplitude, localized structures, thus facilitating the selection of the eigenfrequency. We demonstrate that the dependence of the variance of coefficients on the wavelet level during a geomagnetic storm event is characteristically different from that obtained from data on a day associated with quiet geomagnetic activity. This suggests that the spectral nature of magnetic disturbances excited in the magnetosphere is dependent upon the level of geomagnetic activity.

Suppose that Ω = {1, 2,…, ab } for some non-negative integers a and b . Denote by P ( a , b ) the set of unordered partitions of Ω into a parts of cardinality b . In this paper we study the decomposition of the permutation module C P ( a , b ) where C is the field of complex numbers. In particular, we show that C P (3, b ) is isomorphic to a submodule of C P ( b , 3) for b ≥ 3. This settles the next unproven case of a conjecture of Foulkes.

Epidermoid cysts are rare lesions accounting for 1% of intracranial tumors with approximately 50% located within the cerebello-pontine angle (CPA). Resection is complicated by their close anatomical relation to critical neurovascular structures and their tendency to be densely adherent making complete removal a significant neurosurgical challenge. We present a 35-year-old woman with left sided tongue numbness and lower lip paresthesias with a CPA epidermoid. An endoscopic assisted retrosigmoid approach was utilized for resection. A 30-degree endoscope was used to assist in removal of unseen tumor in Meckel's cave, medial to the lower cranial nerves, and along the ventral pons.The video can be found here: http://youtu.be/bv0lMPbX7BY.

It is difficult to estimate how much distributed generation (DG) capacity will be connected to distribution systems in the coming years, however, it is certain that increasing penetration levels require robust tools that help assess the capabilities and requirements of the networks in order to produce the best planning and control strategies. The work of this Task Force is focused on the numerous strategies and methods that have been developed in recent years to address DG integration and planning. This paper contains a critical review of the work in this field. Although there have been numerous publications in this area, widespread implementation of the methods has not taken place. The barriers to implementation of the advanced techniques are outlined, highlighting why network operators have been slow to pick up on the research to date. Furthermore, key challenges ahead which remain to be tackled are also described, many of which have come into clear focus with the current drive towards smarter distribution networks.

FLAGPOL, a large-scale linear-programming model of the production, distribution, and inventory operations in the flat glass business of Libbey-Owens-Ford deals with four plants, over 200 products, and over 40 demand centers in a 12-month planning horizon. Annual savings from a variety of sources are estimated at over $2,000,000.

Aim: To assess the functional outcome following internal fixation with the PHILOS (proximal humeral interlocking system) for displaced proximal humeral fractures. Patients and Methods: We reviewed 30 consecutive patients treated surgically with the proximal humeral locking plate for a displaced proximal humeral fracture. Functional outcome was determined using the American Shoulder and Elbow Society (ASES) score and Constant Murley score. Results: Average age of the patients was 58 years (range, 19-92 years). The average overall ASES score was 66.5. The average overall Constant score was 57.5. Conclusion: Our results show that good fracture stability was achieved, and the functional outcome was very good in younger patients and it declined with increasing age. Early mobilization of the shoulder can be achieved without compromising fracture union.

Human respiratory syncytial virus (HRSV) is the leading cause of lower respiratory tract disease in infants. The HRSV small hydrophobic (SH) protein plays an important role in HRSV pathogenesis, although its mode of action is unclear. Analysis of the ability of SH protein to induce membrane permeability and form homo-oligomers suggests it acts as a viroporin. For the first time, we directly observed functional SH protein using electron microscopy, which revealed SH forms multimeric ring-like objects with a prominent central stained region. Based on current and existing functional data, we propose this region represents the channel that mediates membrane permeability.Structured summaryMINT-7890792, MINT-7890805: SH (uniprotkb:P04852) and SH (uniprotkb:P04852) bind (MI:0407) by chromatography technology (MI:0091)MINT-7890784, MINT-7890776: SH (uniprotkb:P04852) and SH (uniprotkb:P04852) bind (MI:0407) by electron microscopy (MI:0040)

Maize streak virus (MSV; Genus Mastrevirus, Family Geminiviridae) occurs throughout Africa, where it causes what is probably the most serious viral crop disease on the continent. It is obligately transmitted by as many as six leafhopper species in the Genus Cicadulina, but mainly by C. mbila Naudé and C. storeyi. In addition to maize, it can infect over 80 other species in the Family Poaceae. Whereas 11 strains of MSV are currently known, only the MSV‐A strain is known to cause economically significant streak disease in maize. Severe maize streak disease (MSD) manifests as pronounced, continuous parallel chlorotic streaks on leaves, with severe stunting of the affected plant and, usuallly, a failure to produce complete cobs or seed. Natural resistance to MSV in maize, and/or maize infections caused by non‐maize‐adapted MSV strains, can result in narrow, interrupted streaks and no obvious yield losses. MSV epidemiology is primarily governed by environmental influences on its vector species, resulting in erratic epidemics every 3–10 years. Even in epidemic years, disease incidences can vary from a few infected plants per field, with little associated yield loss, to 100% infection rates and complete yield loss. Taxonomy: The only virus species known to cause MSD is MSV, the type member of the Genus Mastrevirus in the Family Geminiviridae. In addition to the MSV‐A strain, which causes the most severe form of streak disease in maize, 10 other MSV strains (MSV‐B to MSV‐K) are known to infect barley, wheat, oats, rye, sugarcane, millet and many wild, mostly annual, grass species. Seven other mastrevirus species, many with host and geographical ranges partially overlapping those of MSV, appear to infect primarily perennial grasses. Physical properties: MSV and all related grass mastreviruses have single‐component, circular, single‐stranded DNA genomes of approximately 2700 bases, encapsidated in 22 × 38‐nm geminate particles comprising two incomplete T = 1 icosahedra, with 22 pentameric capsomers composed of a single 32‐kDa capsid protein. Particles are generally stable in buffers of pH 4–8. Disease symptoms: In infected maize plants, streak disease initially manifests as minute, pale, circular spots on the lowest exposed portion of the youngest leaves. The only leaves that develop symptoms are those formed after infection, with older leaves remaining healthy. As the disease progresses, newer leaves emerge containing streaks up to several millimetres in length along the leaf veins, with primary veins being less affected than secondary or tertiary veins. The streaks are often fused laterally, appearing as narrow, broken, chlorotic stripes, which may extend over the entire length of severely affected leaves. Lesion colour generally varies from white to yellow, with some virus strains causing red pigmentation on maize leaves and abnormal shoot and flower bunching in grasses. Reduced photosynthesis and increased respiration usually lead to a reduction in leaf length and plant height; thus, maize plants infected at an early stage become severely stunted, producing undersized, misshapen cobs or giving no yield at all. Yield loss in susceptible maize is directly related to the time of infection: infected seedlings produce no yield or are killed, whereas plants infected at later times are proportionately less affected. Disease control: Disease avoidance can be practised by only planting maize during the early season when viral inoculum loads are lowest. Leafhopper vectors can also be controlled with insecticides such as carbofuran. However, the development and use of streak‐resistant cultivars is probably the most effective and economically viable means of preventing streak epidemics. Naturally occurring tolerance to MSV (meaning that, although plants become systemically infected, they do not suffer serious yield losses) has been found, which has primarily been attributed to a single gene, msv‐1. However, other MSV resistance genes also exist and improved resistance has been achieved by concentrating these within individual maize genotypes. Whereas true MSV immunity (meaning that plants cannot be symptomatically infected by the virus) has been achieved in lines that include multiple small‐effect resistance genes together with msv‐1, it has proven difficult to transfer this immunity into commercial maize genotypes. An alternative resistance strategy using genetic engineering is currently being investigated in South Africa. Useful websites: 〈http://www.mcb.uct.ac.za/MSV/mastrevirus.htm〉; 〈http://www.danforthcenter.org/iltab/geminiviridae/geminiaccess/mastrevirus/Mastrevirus.htm〉.

Background We have characterised a new highly divergent geminivirus species, Eragrostis curvula streak virus (ECSV), found infecting a hardy perennial South African wild grass. ECSV represents a new genus-level geminivirus lineage, and has a mixture of features normally associated with other specific geminivirus genera. Results Whereas the ECSV genome is predicted to express a replication associated protein (Rep) from an unspliced complementary strand transcript that is most similar to those of begomoviruses, curtoviruses and topocuviruses, its Rep also contains what is apparently a canonical retinoblastoma related protein interaction motif such as that found in mastreviruses. Similarly, while ECSV has the same unusual TAAGATTCC virion strand replication origin nonanucleotide found in another recently described divergent geminivirus, Beet curly top Iran virus (BCTIV), the rest of the transcription and replication origin is structurally more similar to those found in begomoviruses and curtoviruses than it is to those found in BCTIV and mastreviruses. ECSV also has what might be a homologue of the begomovirus transcription activator protein gene found in begomoviruses, a mastrevirus-like coat protein gene and two intergenic regions. Conclusion Although it superficially resembles a chimaera of geminiviruses from different genera, the ECSV genome is not obviously recombinant, implying that the features it shares with other geminiviruses are those that were probably present within the last common ancestor of these viruses. In addition to inferring how the ancestral geminivirus genome may have looked, we use the discovery of ECSV to refine various hypotheses regarding the recombinant origins of the major geminivirus lineages.

The fungal cyanide hydratases form a functionally specialized subset of the nitrilases which catalyze the hydrolysis of cyanide to formamide with high specificity. These hold great promise for the bioremediation of cyanide wastes. The low resolution (3.0 nm) three-dimensional reconstruction of negatively stained recombinant cyanide hydratase fibers from the saprophytic fungus Neurospora crassa by iterative helical real space reconstruction reveals that enzyme fibers display left-handed D(1) S(5.4) symmetry with a helical rise of 1.36 nm. This arrangement differs from previously characterized microbial nitrilases which demonstrate a structure built along similar principles but with a reduced helical twist. The cyanide hydratase assembly is stabilized by two dyadic interactions between dimers across the one-start helical groove. Docking of a homology-derived atomic model into the experimentally determined negative stain envelope suggests the location of charged residues which may form salt bridges and stabilize the helix.

We analysed the outcome of the Coonrad-Morrey total elbow replacement used for fracture of the distal humerus in elderly patients with no evidence of inflammatory arthritis and compared the results for early versus delayed treatment. We studied a total of 32 patients with 15 in the early treatment group and 17 in the delayed treatment group. The mean follow-up was 56.1 months (18 to 88). The percentage of excellent to good results based on the Mayo elbow performance score was not significantly different, 84% in the early group and 79% in the delayed group. Subjective satisfaction was 92% in both the groups. One patient in the early group developed chronic regional pain syndrome and another type 4 aseptic loosening. Two elbows in the early group also showed type 1 radiological loosening. Two patients in the delayed group had an infection, two an ulnar nerve palsy, one developed heterotopic ossification and one type 4 aseptic loosening. Two elbows in this group also showed type 1 radiological loosening. The Kaplan-Meier survivorship analysis for the early and delayed treatment groups was 93% at 88 months and 76% at 84 months, respectively. No significant difference was found between the two groups.

[1] Using CANOPUS, GREENLAND, IMAGE, SAMNET, and 210 MM ground-based magnetometer array data, we examine the global characteristics of ULF waves during the onset day of the great magnetic storm of 24 March 1991. We focus on the main phase in the period of decreasing Dst and investigate the characteristics of discrete frequency Pc5 pulsations. Pc5 pulsations with multiple discrete spectral peaks including a 2.8 mHz pulsation were seen at 0815–0915 UT, and a monochromatic 1.9 mHz wave appeared at 1010–1110 UT. Also, a very monochromatic and large-amplitude 1.7 mHz wave was observed at 1200–1340 UT across a wide range of dayside local times and at unusually low latitudes. We have analyzed the amplitude and phase relationships of waves at these frequencies. The 2.8 mHz, 1.9 mHz, and 1.7 mHz spectral peaks have maximum amplitudes at L = 3.6, L = 4, and L = 4.3, respectively, and exhibit the characteristic features of field line resonances (FLRs). The discrete mHz frequencies are consistent with some of the discrete peaks seen by Samson et al. (1992) and support the hypothesis of the existence of MHD cavity or waveguide modes in the magnetosphere. However, our results show evidence for the penetration of ULF wave power in the Pc5 band to much lower L-values than normal, suggesting a significant reduction of the local Alfven eigenfrequency continuum as compared to nonstorm times. This may have considerable significance for the interaction between ULF waves and MeV electrons in the outer radiation belt during storms.

[1] This paper presents a coordinated ground-based magnetometer and IMAGE satellite study of plasma mass density and plasmapause location on L shells between 2.39 and 6.54 throughout an extended interval of moderate geomagnetic activity from 5 to 17 May 2001. Storm-time plasmaspheric depletion is monitored using three different data sets, and our results show the importance of local time history effects on plasma depletion, including determining that shorter intervals of enhanced convection do not necessarily cause all meridian sectors to be depleted. Analysis of ground-based magnetometer derived mass density implies that poststorm refilling is not a steady process through the dayside sector. Our results also suggest that refilling may be a two-stage process, operating with a much increased rate on the third day of clear refilling. Comparisons between time-dependent ground-based magnetometer cross-phase and IMAGE RPI determined plasma mass density profile evolution imply the presence of an enhanced heavy ion population in the inner plasmatrough during an active refilling interval. These results further demonstrate the potential of using ground-based magnetometer data to study cold plasma dynamics.

[1] The structure of the density discontinuity across the plasmapause is often based on electron and H+ density profiles with the contribution of heavy ions (He+, O+ etc) neglected. Electron and ion density measurements in this region may differ significantly due to the presence of heavy ions and it is important for the intercomparison of different datasets to understand these differences. Dynamics Explorer (DE-1) magnetic field and plasma composition data have been used to compare heavy ion responses across the plasmapause and to calculate the mass loaded ion density (ρ) profiles. To illustrate this we investigate mass loading through radial profile variations in the Alfven velocity (VA). Results show that the gradient in ρ and VA across the plasmapause is modified when mass loading due to multiple heavy ion species is included, particularly in the presence of the O+ torus. Application to ultra-low frequency (ULF) field line resonance is used as an example where the contribution from heavy ions smoothes out the expected ULF wave resonant frequency discontinuity at the plasmapause.

Cold plasma mass density profiles in the plasmasphere have been determined for the geomagnetically quiet day of 19th August 2000 using the cross-phase technique applied to ground-based magnetometer data from the SAMNET, IMAGE and BGS magnetometer arrays. Cross-phase derived mass densities have been compared to electron densities derived from both ground-based VLF receiver measurements, and the IMAGE satellite RPI. The cross-phase results are in excellent agreement with both the VLF and IMAGE observational results, thus validating the cross-phase technique during quiet times. This is the first such coordinated multi-instrument study, and has enabled very few heavy ions to be inferred in the plasmasphere for L > 3.45 on this day. The observational results were compared to plasma mass densities from the SUPIM model and were found to be in excellent agreement. IMAGE EUV data also verified the existence of azimuthal structure in the outer quiet-time plasmasphere.

BACKGROUND: It is recognized that endothelins are released in response to hypoperfusion and anoxia of the kidney and may be responsible for the consequent deterioration in renal function. This study examined the ability of a non-selective (SB209670) and ET(A)-selective (UK-350,926) endothelin antagonist to attenuate ischaemia-induced renal failure in unilaterally nephrectomized rats. METHODS: The animals were anaesthetized, drug infusion commenced, and the renal artery occluded for 30 min. The endothelin antagonists were given for 30 min before, during, and 60 min after the ischaemic period, at 10, 30 and 100 micro g/kg/min or for 60 min after the start of reperfusion. RESULTS: On day 1, following 30 min renal artery occlusion, there was a 95% reduction in glomerular filtration rate, an 8-10-fold increase in plasma creatinine, and 10-15-fold increases in fractional excretions of sodium and potassium, which were partially resolved on day 3 and normalized on day 8. The lowest dose of SB209670 was without effect on the renal functional responses but they were blunted (all P

We examined the prevalence and correlates of condom use in a community-based sample of unmarried heterosexual and gay/bisexual Whites, Blacks, and Hispanics (aged 20 to 44 years) in San Francisco (n = 1229). Only 9% of heterosexual males reported always using condoms, and fewer of those with multiple sexual partners (6%) reported always using condoms compared with those in monogamous relationships (12%). Much higher proportions of gay/bisexual men reported always using condoms (48%). Racial differences in condom use were observed only among women. Sexual communication and the sexual enjoyment value of condoms were consistent correlates of condom use across gender and sexual orientation, while other condom-related beliefs were significant predictors of condom use only for men. In general, condom promotion programs should build sexual communication skills, teach people how to enhance enjoyment with condoms, and reduce psychological barriers to condom acquisition and use.

There is little information in the literature regarding the clinical features, investigation, diagnosis and treatment of closed rupture of the deep transverse metacarpal ligament. We demonstrate a case with previously undescribed features and describe the surgical management.

Growing perceptions that ecological research is failing to meet the needs of resource managers has prompted a review of the structure and management of research programmes. In this paper we identify principles, frameworks and approaches to guide the restructuring of research programmes. Their application is discussed in relation to the restructured research programme on the rivers flowing through the Kruger National Park. A preliminary evaluation after one year of operation of this programme indicated beneficial changes in research and in stakeholder and client attitudes to research.

Application of the engine CFD code KIVA II with the inclusion of the SHELL model for autoiginition chemistry, and the discrete transfer radiation heat transfer model, has enabled the technically important problem of non luminous radiation from the major emitting species CO\d2 and H\d2O in the combustion products within the cylinder of a spark ignition engine to be considered as a combustion diagnostic aid, and also as a method of controlling individual cylinder Air/Fuel ratio. Results from a parametric study using CFD have been found to corroborate the experimental findings of other workers over a range of operating conditions including knock.

An intervention was developed to promote safer sex and condom use among patients seeking treatment for sexually transmitted disease (STD) at a public health STD clinic in Los Angeles, CA. The intervention consisted of a short group discussion on condom use, a presentation of a videotape portraying condom use as socially acceptable behavior, and a role-playing session concerning negotiating the use of a condom with one's sex partner. The study group was 551 persons who visited the clinic in 1988. Medical records of 426 (77 percent) were located and reviewed 7 to 9 months later. Among those, 220 had participated in the intervention and 206 were control subjects who had not participated in the intervention. The rates at which patients reacquired STD after treatment and after the intervention were compared between the intervention group and the control group. Men who participated in the intervention subsequently showed a lower rate of STD reinfection than those who did not. There was no evidence that the intervention reduced reinfection among women. The strongest predictor of reinfection was found to be a history of STD infection prior to the infection that was being treated at the time of the intervention. The results show that group interventions directed to STD patients can be effective in reducing STD reinfection among men.

This paper describes the application of the discrete transfer model of thermal radiation in the engine CFD code KIVA for the simulation of diesel combustion and heat transfer. The comprehensive modelling of flows and heat transfer in engines requires accurate evaluation of transient temperature and radiation properties of the gaseous combustion products. A submodel for autoignition chemistry and a soot formation and oxidation model have been incorporated in the general computational fluid dynamics procedure, and Hottel's mixed grey and clear gas concept has been used to evaluate emissivities. Results of calculations are presented for engine aerodynamics, cylinder pressure and temperature, soot concentration, and radiative heat fluxes. Radiative heat fluxes have been compared with data, in similar experimental engines. Comparisons between the predictions and data show encouraging agreement. Inclusion of the submodels for autoignition and soot formation and combustion seem to have greatly enhanced radiation predictions. It is concluded that present prediction techniques can be useful in providing information in engine flows under a variety of engine operating conditions

The work presented describes the development of an interactive model to simulate a direct injection diesel engine under both steady and transient conditions, based on the application of concurrent process computing methods. Starting with the modelling of the engine under steady operating conditions, in which induction, injection, air entrainment, fuel air mixing, combustion, emission and mechanical friction processes are considered, the fuel pump, governor, engine crankshaft and external load dynamics are also investigated to model the transient behaviour of the engine and its associated load. [Continues.]

We retrospectively evaluated 51 patients (17 in each of three groups) with mid shaft clavicle fractures. Group 1 underwent intramedullary stabilization using clavicle pins. Group 2 underwent open reduction and internal fixation using plates and group 3 underwent non operative treatment with a sling. Group1 patients progressed to union within 8 to 12 weeks. In Group 2, six patients had scar related pain and two had prominent metal work and discomfort and in group 3, three patients developed non union and one had symptomatic malunion. Our results suggest that the displaced and shortened midshaft clavicle fractures require operative fixation and the techniques of clavicle pinning resulted in less complications, short hospital stay and good functional outcome.

The aim of this study was to evaluate the long-term prognosis for patients suffering from gastritis associated with Helicobacter pylori infection, and in particular the proportion of cases progressing to peptic ulcer. The study was carried out in one urban general practice. One hundred and three patients who had presented with dyspepsia over the 1973-80 period and who were found to have a macroscopically normal endoscopy were reassessed between seven and 14 years later. Gastric antral biopsies had been taken routinely at endoscopy and were subsequently re-examined for the presence of H pylori. The patients' medical records were examined to establish their consulting rates over the follow-up period and whether they suffered from any other medical conditions. Patients were interviewed to assess the course of their dyspeptic symptoms. Comparison of patients who were unequivocally H pylori positive with those who were negative revealed no significant differences in the consultation rate for gastroenterological symptoms, in the proportion of patients referred to a hospital consultant or for further gastroenterological investigations or in the proportion reporting that their symptoms had improved. However, a statistically highly significant relationship was found between H pylori infection and hypertension. The results of this study have shown that there is a good prognosis for non-ulcer dyspepsia whether or not H pylori infection is present. The association between H pylori gastritis and hypertension clearly merits further investigation.

This paper presents the results of a study of the air motion in a motored four-stroke direct injection diesel engine using hot-wire anemometry. The effects of engine speed, valve masking and supercharging on mean air swirl have been studied. A theoretical analysis is developed for the mean air swirl which in general shows good agreement with the experiments reported here and with the measurements of other workers on similarly sized engines. The problem of ‘squish’ has been investigated and it is shown to be the radial component of the spiralling swirl flow entering the combustion chamber. Reasonable agreement has been found between measurement of the radial flow component at the edge of the combustion bowl and a theoretical analysis that considers the bulk radial flow of air to the combustion bowl during the last 30°-40° b.t.d.c. of the compression period.

One hundred and fifty isolates of Campylobacter pylori were divided into nine groups by immunoblot fingerprinting. All isolates were typable and reproducibility between immunoblots was good provided both antigen and antibody preparation were standardised. Discrimination was a problem as Groups 1 and 2 accounted for 66% of isolates. Recurrence after bismuth treatment was due to indistinguishable strains in five patients and different strains in three patients.

The presence of C pylori infection was determined in 1445 patients undergoing upper gastrointestinal endoscopy over a 12 month period. The presence of C pylori was detected in gastric mucosal biopsy specimens by the biopsy urease test, microscopy (Gram stained smears and histology) and culture. Two media were used for the biopsy urease test: Christensen's urea broth (for the first 600 patients) and the Christensen's urea broth modified by increasing the concentration of phenol red and omitting the nutrients, glucose and peptone (for the remaining patients). Both the Christensen's urea broth and modified urea broth were almost 100% specific when compared with detection of C pylori by Gram, culture and histopathology. The modified broth was more sensitive (96% sensitivity compared with culture) than the Christensen's broth (92% sensitivity) but this difference was not statistically significant. The modified broth gave significantly more positive results (58%) in less than 30 minutes than the Christensen's broth (48%). Seventy four per cent of positive results were available in less than two hours. Specimens from patients with extensive C pylori infection gave more rapid results: 86% of specimens that yielded a profuse growth of C pylori and 76% that contained numerous organisms on histological sections had a positive urease test in less than one hour. There was no significant difference between the specificity and sensitivity of our modified urea broth and the other modified broths described in the literature. This test is a cheap and rapid alternative to the diagnosis of C pylori by Gram stained smears or culture.